He has known Asaga since they were kids. Despite their strong friendship, Tatsuo envied him slightly because he wasn't affected by any health problems and grew angry with the outside world. One day the two of them split a medallion picturing a stylized dragon, with Asaga taking the lower part and Tatsuo the head as a symbol of their relationship. At some point in their adolescence, he went to Psyren and offered a card to Asaga, although the latter refused.
Tatsuo & the Worm arcEdit
In Psyren, a figure wearing a mask appears, holding a rifle that uses his PSI energy. He strongly resembles Tatsuo and after killing all but the five survivors, takes his aim at them and destroys part of the building. Amamiya says he's a Burst user and he also uses Rise to fight her physically. After using Trance, Amamiya realizes that Tatsuo was transformed into a Tavoo by having an orb implanted into him. Tatsuo regains his mind after being hit by Ageha's Melchsee's Door, however, his core remains because it has been integrated into his body. Because he does not have his card, he stays in Psyren, revealing that he will die when his core runs out of energy but will look for a way around this. He describes his time as a Tavoo as being trapped in someone else's body and regrets all the killings he did.
Third Trip arcEdit
During Hiryu's brief conflict with Shiner, he was teleported 4,000 meters above Psyren to fall to his death, however, he survived by using his PSI to cushion the fall and was later saved by Tatsuo. Tatsuo then shows Hiryu that he has a better understanding of his PSI powers an is now able to create solid guns out of PSI energy and takes him to Kasukabe's hidout.
Q's Master ArcEdit
Q's master shows Ageha, Tatsuo, Hiryu and Kusakabe when Ageha made Q's Master show what happened to Hiryu after he was teleported by Shiner. It was then that Hiryu decides to stay in the future with Tatsuo in order to help him fight W.I.S.E and find a way to return his body back to normal.
He recently returned and joins the battle with the resistance against Scourge. He demonstrates his new abilities and saves Asuka Yoshina from Junas with Hiryu when he shoots the sky, shining sunlight at Junas causing him to suffocate and now after Junas had to escape Tatsuo, Hiryu and Kasukabe team up with the resistance and start their all-out attack on the W.I.S.E.
Gunman (バースト銃, Bāsuto Jū) - Tatsuo is capable of concentrating a large quantity of Burst energy into various types of bullets. Their destructive potential is such that they can easily pierce concrete structures, subsequently obliterating the hit object with a resultant explosion. Tatsuo initially required an appropriate medium with which to conduct his ability through a large rifle that feds off his PSI and that has to be recharged after 4 shots. The reloading process is to be done by pouring PSI in all the bullets simultaneously. It was thought that it required more than an hour, but that was just a deception operated by Tatsuo since actually, he can recharge his weapon in a matter of seconds. After he was saved by Kusakabe, he learnt to conjure his weapons out of PSI alone. Those include small guns of unknown power and a much larger sniper whose beams can even reach and pierce the clouds, generating large holes in the process.
Proficient - Tatsuo is adept in the employment of this specific element of PSI; typically utilizing it to fight when he is recharging his PSI to use his Burst and to increase the maximum destruction of his blows. He also uses it to support his regular movements while partaking in confrontations, substantially increasing his respective speed and strength. Thanks to his considerable endurance, Tatsuo is able to maintain this variant for extended periods of time, aptly demonstrated when he took multiple hits from Ageha. Tatsuo's good at Rise but is an inexperienced fighter, being at a disadvantage when facing experienced ones. It should be noted that Tatsuo suffers from an illness that physically weakens his body. After undergoing Illumina Forge he uses Rise in order to overcome this physical weakness.
Unknown - During his brief period of activity within the series, Tatsuo failed to demonstrate any affinity to this form of PSI, instead preferring to rely solely on his extensive Burst abilities in combination with Rise. However, it was never explicitly expressed that he was incapable of using it, although he was unable to counter Amamiya's, Mind Jack.
|Ageha Yoshina - Sakurako Amamiya - Hiryū Asaga - Oboro Mochizuki - Kabuto Kirisaki|
|Elmore Wood School|
|Elmore Tenjuin - Frederica Tenjuin - Marie Tenjuin - Shao Tenjuin - Kyle Tenjuin - Van Tenjuin|
|Lan Shinonome - Haruhiko Yumeji - Chika Shinonome - Ian - Fubuki Yoshina - Asuka Yoshina|
|Tatsuo Mana - Yuusuke Kusakabe|
|Psychicer - Tavoo|