Koreyuki has light brown hair that is cut into a bowl-shaped haircut and brown eyes.
Koreyuki is a bit smug and a little arrogant.
Before Satoshi Fukube goes up to his designated buzzer for the Quiz Trial 7, one other participant calls to him. Satoshi recognizes that this person is "Tani-kun" from the Go Club. Before they can talk about something interesting that happened in the Go club, Satoshi has to go and introduce himself to the crowd. Koreyuki and Satoshi lose in the Quiz Trial, and then Koreyuki informs him that the Go Club had some playing stones chosen. He then challenges Satoshi in the cooking competition that was set for the next day and Koreyuki loses the cooking competition to Satoshi.
He then appears as one of the wannabe detectives trying to rat out Jūmonji.
Koreyuki sees himself as Satoshi's rival, although by the looks of it, Satoshi only finds him annoying.
- The name Koreyuki means "consider, reflect, think" (惟) (kore) and "this" (之) (yuki).
- Koreyuki's surname Tani means "valley" (谷).
|Classic Literature Club series and Hyouka featured characters|