In Chapter 3, it is revealed that Tarou is an extreme masochist (comedy style). He wants to be teased. The girls are actually his childhood friends who realized long ago that the only way to get him to smile is to bully him. The "Proof" isn't slavery—it’s a pact of mutual weirdness.
You hate repetitive slapstick, or if the word "Baka" triggers your fight-or-flight response. Also, avoid if you need a wholesome romance—this is 80% vinegar, 20% sugar.