Skim by Mariko Tomaki, illustrated by Jillian Tomaki

From chapters.ca:
The time is the early 1990s, the setting a girls' academy in Toronto. Enter "Skim," aka Kimberly Keiko Cameron, a not- slim, would- be Wiccan goth. When her classmate Katie Matthews is dumped by her boyfriend, who then kills himself, the entire school goes into mourning overdrive. It's a weird time to fall in love, but Skim does just that after secret meetings with her neo- hippie English teacher, Ms. Archer. When Ms. Archer abruptly leaves the school, Skim has to cope with her confusion and isolation, as her best friend, Lisa, tries to pull her into "real" life by setting up a hilarious double date for the school's semi- formal. Skim finds an unexpected ally in Katie. Suicide, depression, love, being gay or not, crushes, cliques of popular, manipulative peers - the whole gamut of tortured teen life is explored in this masterful graphic novel by cousins Mariko and Jillian Tamaki.