Jukai Shounen Zoo 1樹海少年ZOO１ ; Jukai Shounen Zu-ichi ; Nature Boy Zoo-Ichi

A high-school kid who’s a total loser throws up a lot. That’s about it. 25% of the manga is Juichi (the title is a pun on his name) throwing up or sneezing in full page spreads. It’s total madness.