Kaidou Toki

Toki Kaidou (海藤 時, かいどう とき lit. Kaidou Toki) is Shun's little brother who looks up to him because of his great accomplishments like being a gang leader and a savior. These were all actually exaggerations Shun made after boasting about himself.

Personality
Toki is fond of Shun and looks down on others like Kusuo and Riki whom he thought were his brother's underlings. He was revealed to be stronger than Shun as he was able to flip a delinquent high school student.

Appearance
Toki bears striking resemblance to Shun's pre-chuunibyou appearance with his hair down. It is implied that he was copying Shun's style of clothing like wearing long sleeves when Shun wears long sleeves or collared shirt.

Trivia

 * His name, along with his sister's, is based off of time-space travel (時空間移動, lit. jikūkan idō), whereas his name comes from the single kanji for time, (時, lit. toki), which, when contextually combined with the kanji for sky (空, lit. sora), means time-space (時空, lit. jikū).
 * In an unused draft for Chapter 51, a precursor to Toki, under the name Kaidou Haru (海藤 春, かいどう はる), makes an appearance. His design and age differs from what he would eventually become, though, similar to Toki, he believes Shun’s chuunibyou delusions.
 * The name Kaidou Haru is derived from the Japanese term for teleportation (瞬間移動,しゅんかんいどう lit. shunkan idō) as “shun” is an alternative reading of 春.