He was a fan Domon as a Pro-Fighter before he met him and in the year 2000, he loves Domon and wishes he can be just as good as him. In Episode 4, he wants so badly to be useful to someone, and eventually goes to Domon where the other man is passing out fliers. Domon is only going to women, and when Sion questions him about it, Domon tells Sion that it doesn't matter who loves who, so Sion then tells him he loves him. Domon thankfully knew exactly what the boy meant, the trouble was this announcement was made loudly in a crowd in the streets--especially in front of a pretty woman Domon was trying to get to join his self-defense class. But Domon manages to lose Sion, who wants him to teach him how to fight so he can be a good Time Ranger. When Domon finds out about Sion's past after he gets kidnapped, Domon feels guilty and from then on, defends him. For the first time, Sopm has an older brother to watch out for him. Sion is willing to believe the best about anyone, he always puts himself between Domon and Ayase. He sensibly urges they use their strength only against the enemy. It is Sion who is the only one not troubled by being a thousand years in the past, because he has nothing in the 31st century. Here in the past, he will happily live anywhere as long as he is with the others. He respects Ayase's bravery and smarts. When he finds out Ayase is dying, his first reaction is to refuse to believe it. And he gets angry with him for not allowing him to care. As for Yuuri, he knows exactly how it feels to be orphaned and alone, though the extent of her anger often bewilders h im.
He thinks Tatsuya is wonderful, for that one has come to take care of them and help them get along in this world. Just as Sion wants an older brother, Tatsuya wants a younger. Like Tatsuya, Sion calls Naoto by his given name. He also thinks Naoto is about the most wonderful fighter and shot in the world, ignoring his irritableness because it is much less for Sion than it is for others. In Episode 32, Sion has to rescue a Londarz prisoner who is being forced into agonized fighting by Gien. He has to rescue it first from Gien and Lila, then from Time Fire who is intent to kill it. It is up to Sion to finally get across to Naoto that these are not monsters to be destroyed, but only alien criminals. Naoto wouldn't listen to the others, but Sion's sweet innocence and seeming hysterical determination get through to the man. In episode 45, Sion gives Naoto a present he's made: a personal arresting badge for Time Fire. Naoto has been adopted into the group despite himself. And in the end, it is Naoto who moves in to help Sion. Captain Ryuuya is the only one to truly anger Sion. His cold-hearted outlook for his own interests drives Sion a tad frantic, until it is Domon who has to hold our youngster back.
In Episode 12, Sion stumbles upon another alien, hiding on Earth to avoid a war on his home planet. But he has been discovered by a Londarz and forced to steal things. The criminal can teleport only inorganic objects. Sion tries to help free him from Londarz control on his own, but when team notices his unhappiness, they eventually help him. Sion is quicker to notice someone's emotions. Namely, those of Honami who fell in love with Domon. And he is all too willing to help, so he gives her his e-mail address so that she can write to Time Yellow. And it is also him who notices most quickly what is really troubling Domon about his situation with Honami. In Episode 21, the others are under the influence of a liquid that makes them behave like happy drunkards. Sion is immune to the effect and must face a deadly enemy on his own. He quickly creates a machine that will teach him the speed the other has, and manages to modify the Time Suits to compensate with a special speed attack called the Accel Stop. When the others finally recover, they discover to their horror that Sion took pictures of them in their condition. In Episode 23, Sion designs the a powerful weapon known as the Assault Vector to transform the Double Vector from a slashing blade into a fire-arm.
In Episode 27, Sion meets an elderly man who has moved to the ocean. The man teaches Sion about making himself part of a place, making it his birthplace even when he is not from anywhere near it. And the man plants a young tree for Sion, making that his place as well. Like the tree, Sion can put down roots. Sion then creates Robota, the tiny blue robot made to help Takku. In Episode 38, Sion takes his yearly week-long slumber and dreamt that a mad alien director takes control of their lives. Tricked onto the set of a movie, thinking it was really a ninja movie with his favorite actor. Sion, so tired he almost cannot stand, is surrounded by his friends who act to protect him from the attacks, and Yuuri tells him there is no way he could be anything other than useful. During Sion's first Christmas, he who writes wishes and prayers, attaching them to the tree they'd bought asking Tatsuya to come back to them. In Episode 46, Sion repairs Takku, only to find Takku is convinced he can't be useful to them any more. Takku has found that any data they really need to know is not in his systems. Sion protests that he doen't have the power to help anyone, but he wants to help. He and Takku succeed in saving the day. He frets because he wants to save the 20th and worries of that makes him a bad person. It doesn't because of course Sion's heart is in the right place and he decides to makes the only choice he can, wrong or right.