Konjiki no Word Master: Yuusha Yonin ni Makikomareta Unique Cheat

Okamura Hiiro is introverted and loves books. To him, books are his raison d'etre. His story starts with usual gimmick of summoning of heroes. Five people summoned, but one of them is just an outsider dragged in accidentally, that person is Hiiro. The four others are his classmates, but it's not like they are friends. Unlike him, they are riajuus....