Spoilers are bad. Especially when you spoil the favorite anime to a member of the kendo club (who happens to carry around a katana).

When Terada accidentally lets slip a spoiler about Hikami’s favorite anime, only bad things can happen. From then on, Terada can only try to survive the increasingly extreme measures Hikami uses to take vengeance. It can only be described as a war – a spoiler war.

(Source: Suimasen Scans)