Journey to Palaestra
A new friend
He first meets Koga when he is searching for recent detection of a huge Cosmo explosion when meeting the young Pegasus, teasing him for not knowing his element, and later teaches him how it works. When he asks Koga why he is travelling, the young Pegasus responds with that Athena was kidnapped, but Souma does not believe him, saying that Athena was at the school, quickly gaining Koga's attention who then demanded to know where she was, and thus Souma decided to take Koga with him to Palaestra in order to become stronger and meet Athena. However, it was not so easy to just travel to the school, as one of the Martians had pursued them and was going to kill them. Koga, who did not know his element yet, was told by Souma to stay out of the battle, and let him handle it, equipping his Lionet Cloth and fight only to be outmatched when he became enshrouded in Ordykia's Dark Mist and did not have any chance to fight back, however Koga saved him by discovering his Light Element and used it in order to allow Souma a powerful blow on the Martian.
Koga and Souma became very close friends from then on, training together and they always hung together when they finally reached Palaestra. The day the battles between Bronze Saints started, Souma fought his first opponent while Koga waited downstairs, as they promised to fight each other in the tournament. After Koga had fought and won against Hook, the time for the best friends had come, and they both fought hard, promising to win and get the chance of becoming a Silver Saint, as that was the reward for the winner of the tournament. However, Souma's best move was outclassed by the legendary Ryu Sei Ken of Koga and he acknowledged defeat, showing great surprise too when Koga learned that move.
However, the tournament was interupted by the Martian forces who took over Palaestra and learned that the school was a trap in order to gather the Cosmo from the students and use it in the creation of Babel. Souma escaped with Yuna and Ryuho before reuniting with Koga and Haruto, before heading away from Palaestra and to save a mysterious girl Koga encountered. After rescuing her, Micene arrived and Koga, Souma, Ryuho and Haruto stayed behind to fight the Gold Saint and buy Yuna time to escape. All their efforts proved to be useless and they were defeated one by one.
"She killed my father!"
Souma arrived as Yuna struggled to stay alive against two Silver Saints and a High artian, whom Souma recognized to be Sonia, the one who killed his father, and he has swore since then to avenge his death. However, the Silver Saints stood in his path, and he and Yuna was forced to fight them instead, only to be defeated and saved by Koga's timely arrival.
Disrupting the tower of Babel
Wind Core Souma joins Koga in the quest of destroying the Cores holding up the tower of Babel and they start with the wind ruin where Souma stays inside to take care of Aria while Yuna and Koga head inside the huge whirlwind. But when Haruto arrives and informs Souma that a Silver Saint is inside there, he decides to head in and help, but by the time the three youngsters have gotten inside the whirlwind, Koga has already defeated the Silver Saint, and Yuna is destroying the Wind Core.
From there, the Saints continue their journey to the Earth Core where Souma and Yuna have to fight the Golems of Michellangelo and Koga must face Ichi who betrayed them. The battle becomes more difficult for Souma and Yuna as they were wounded by Ichi's poisonus hydra fangs, but they manage to survive long enough for Haruto to destroy the Earth Core, and the Golems disingrate as the Earth Silver Saint retreats from battle.
Trying to get a fare
After the battle against Ichi and the golems, the Saints tries to get work at a hotel in order to get money and travel across the sea, but it does not go to well for them. However, the Martians arrive and they must fight them in order to protect the civillians nearby, and they manage to defeat them after a short battle.
Another Silver Saint
He joins Koga and Yuna to the desert mountains where they meet Raki who is looking for Stardust Sand and they are suddenly faced by Dorie. Yuna and Souma are defeated and their Cloths get some battle scratches, which Raki repairs with some Stardust Sand.
In the next ruins, the Flame Ruins, Souma encounters Sonia again and because he lost his control of his emotions, he startet punching like a wild animal after Sonia, and his loss of control over his anger, let him achieve the unstable Cosmo of a Silver Saint as Sonia noted, and decided to use that to her advantage. However, Koga managed to calm down Souma, and he struck Sonia with a well focused blow, finally wounding her. But he was not done with that. He left the team, promising to return once he had settled his score with Sonia.
The Lionet returns
As promised, Souma did return after Koga and his friends invaded the tower of Babel again in order to rescue Aria again, as she had been brought back by Eden during his abscence. After saving Yuna and Koga by defeating Ennead, Souma reveals that he searched for Sonia, but came across Jabu and trained in order to become much stronger, and that was the secret of how he defeated the Silver Saint in one blow. He had another fight against Sonia, once again, ending the battle in a draw.
He then finally joined the other Bronze Saints again and travelled to the Thunder Ruins, where he fell down to the Darkness Ruins along with the other teenagers including Sonia and Eden.
Memories of the past
While facing his and Sonia's memory, Souma saw that Sonia suffered from having killed Kazuma, and was later summoned to Mars where he told her he was not her father, and tried to get rid of her, but Souma saw through the illusion, and saved Sonia, claiming that no one but him would settle the score between them. Souma was also present when Koga and the others fought against Mars and witnessed Aria getting killed by the great God.
The Twelve Temples Battle
After witnessing Aria's death, Souma was teleported with the other Bronze Saints to the staircase which ascended further up to a great flower plain at the top. Joining Koga and the others, Souma climb the staircases and his Cloth is fixed by Kiki before heading to the second temple, where he tries to fight Harbinger, but is defeated.
After Harbinger sends off all Kouga's friends away, Souma and Haruto find themselves on their way to the fifth temple, where they once again would encounter Micene, but prove a more powerful fight this time, as they had a greater reason to fight. After a long fight, Haruto sacrificed himself taking the full blow of the King's Emblem, with Souma burning his Cosmo and managing to crack Micene's Gold Cloth, and he acknowledges their bravery and allows them to pass through the temple.
Souma and Haruto then continued to the Virgo Temple, where they were easily defeated by Fudo. However, they were saved by the timely arrival of Koga, Yuna and Ryuho, with everyone reuniting again. But even though all five had arrived together, they could not defeat the powerful Gold Saint, and was about to be killed when Eden joined the fight, rebelling against his own father.
Final battle at Scorpio Temple
With Eden fighting Fudo, the rest of the Bronze Saints kept going to the Libra Temple where they were attacked by Tokisada and saved by Genbu, before heading onward to Scorpio Temple, where Souma and Sonia, now wearing a Gold Cloth, would fight their final battle. However, Sonia could not handle the tremendous power of the Gold Cloth, and it's power culiminated in her own death, and Souma could not save her, in spite of awakening his Seventh Sense, and was instead granted a sad victory as his father had died, but he did not want her to die like that.
A heroic Lionet
He joined Haruto and Ryuho in defeating the Four Heavenly Kings at the final temple, and joined the Bronze Saints in restraining Koga/Abzu from killing Athena, but they were overpowered. Souma's last act in the battle, was to give his Cosmo alongside the other Bronze Saints to Koga and help him defeat Abzu once and for all.
A new threat rises
A year after the defeat of Abzu, Souma has been taking place as a student-teacher at the Palaestra, teaching the newcomers what it means to be a Saint, and is happy to see Koga again, but is wondered by who Koga's new friend is. Later, Souma ask Koga what the big box he has been carrying is, with Kouga responding that it's his new Cloth, and Souma is shocked that Koga has gotten an upgrade, while his own Cloth is still the same, with all the damage from the battle against Abzu. However, he still dons it when he decides to join Koga and fight the Tertiary Pallasite Loge, but he can not defeat the Pallasite, as his Cloth is to weak to keep up to the new enemy, but he is saved by Koga. After Loge retreats, Souma agrees to travel to Jamir in order to fix his Lionet Cloth. After fixing it, he joins Yuna in her new Cloth and defeat the Tertiary Pallasite siblings Methone and Ymir and their new power make the siblings retreat.
Joining his friends to Pallasvelda to fight the Pallasites, Souma encounters Loge and has his Cloth heavily damaged by the Pallasite. With the help from Subaru and two other Steel Saints, Souma finally managed to kill Loge before they moved on after losing Kerry.
Souma and Yuna encounter Methone again who kill his sister to become stronger. Realising that they can not defeat him by themselves, Yuna and Souma work together, developing a new technique together, defeating the Pallasite.
Souma joins Koga, Yuna and Shun through Alfheim, encountering the Class 2-Pallasite Surtr. After a long battle, Yuna and Souma distract Surtr, allowing Koga to enter the Cosmo Barrier and Shun to defeat the Pallasite.
Encountering Aegaeon, Souma attacks along with his fellow Bronze Saints, but is easily defeated by the Class 1-Pallasite. He moves onward with the others after Ikki takes over the fight.
Souma keeps running in the infinite corridor along with Koga, Yuna and Shun as the two Gemini twins Paradox and Integra fight Gallia. After their combined Another Dimension attack, Souma and the other Saints reunite at the battlefield and notice Paradox dying in Integra's arms.
Sending Athena and the Gold Saints ahead, the Bronze Saints face Gallia, struggling to defeat her as she is a Class 1-Pallasite who easily defeats them. However, after Subaru first awakens his immense Cosmo and later protects his friends from Gallia's strongest technique, Souma and the others awake Omega and they finally manage to defeat Gallia.
Flame Desperado: Souma burns his Cosmo, and his left hand starts to burn as he punches his enemy with a burning force.
Lionet Burning Fire: A more powerful move than Flame Desperado, as Souma gathers his Cosmo into his left hand and sends a huge wall of fire against his enemy. It is quite similar to Kouga's Ryu Sei Ken in some ways and more similiar to Dorie's Cerberus Hell Flare.
Lionet Bomber: Souma burns his Cosmo and launches himself at the enemy with a huge power. He learns it while Jabu trains the young Lionet.
Lionet Explosion: Souma's strongest move, as he gathers his Cosmo into one huge ball of fire which he launces at his enemy. He first used this move while fighting against the Heavenly Kings of Mars.
Lionet Flare Storm Bomber: A new technique Souma learns while he and Yuna fight Methone who killed and merged his sister Ymir with his own, becoming much more powerful. After Yuna attacked, Souma jumped into her attack and burned his Cosmo, defeating Methone and destroying his Chronotector.
Kyu Cloth Souma wears the new version of the Lionet Bronze Cloth, which fully covers his chest, most of the legs and arms, and one of the shoulderplates cross over Souma's heart, forming an orange circle where his heart is.
Before the Bronze Saints can move ahead through the twelve temples, Kiki repairs their Cloths. Souma's repaired Cloth seems to have merged his left shoulder with his left arm, mergin them into one piece of the Cloth.
The new Lionet Cloth in Season 2 covers the upper part of Souma's chest, fully covering his arms, his legs change shape, a belt, and he gains claws at his fists.
When Souma reaches the Omega, he gains claws at his feet, and his Cosmo and strength are increased more than before, as he managed to crack one of Gallia's shoulderplates with one single kick.
During the battle against Hyperion, Souma's Cloth is totally destroyed as they desperately try to defeat the Pallasite. As they get up and burn their Cosmo once more, they reach the Macro Cosmo, finally awakening their true Omega. Souma's Omega Cloth covers almost 100% of his body, still leaving his stomach exposed, with the upper chest being protected, wings have sprouted from his back, golden inlays have also been added to the Cloth, his shoulders have changed shape, and a Lionet symbol has appeared on his chest.
- Souma is left handed, probably the reason for why the Cloth Kiki repaired covered Souma's left arm completely while Koga's repaired Cloth covered his right arm completely.
- Souma is the first Bronze Saint who managed to crack a Gold Cloth even in spite of not having reached his 7th sense completely yet, he first achieved it while trying to save a dying Sonia.
- Souma and Sonia have fought each other three times:
- 1st time was in the Fire Ruins, ended with Sonia retreating after being wounded
- 2nd time was at the Tower of Babel, ended in a draw
- 3rd time was at the Scorpio Temple, ended with Sonia's death
- Souma is the fourth Bronze Saint to reach his 7th sense.