We Whose Names Are Letters

I am C? An ordinary college student? My 'comatriot' D-san is the group favorite of the Tokyo school? Another compatriot of mine, Mr. B, is the elder brother of D-san and is the group favorite of the Kyoto school. ?......? And I am used to set off D's 'Tuanyan'. ……………… Hello everyone, my name is A/B/C/D/E/F/G… First meeting, stranger. Hope to become friends with you. ★ A is in Wen Ye. Purpose: A guide to survival in a dangerous world