He is a side character of Toaru Majutsu no Index. He's the first leader of Skill Out shown in volume SS1 and SS2, best friend with Hamazura Shiage and Hattori Hanzou. Komaba has a younger sister who is in primary school.
Komaba Ritoku is described as gorilla like person. He's pretty big and have a heavy build and large body. He wears black looking clothes, as leather jackets and pants. Even with this aspect, he's a good person who cares about his friends and subordinates.
Komaba Ritoku is a true level 0 with no esper abilites. He uses tactics and technology against his enemies.
As a leader he was respected by all in Skill-Out, and a honourable person in general, forbidding all members to have any connections with prostitution, a method Musujime Awaki said it would have been the fastest way to gather funds and not have to rob banks. Even the targets picked out by Komaba are only those who actively misuse their power on Level 0s, unlike factions such as 'Big Spider' who attack espers indiscriminately.