bokura no sugoi yatsu
ぼくらのスゴイやつ (Our Amazing Things)
A bara manga by Yamakawa Jun'ichi, the author of Kuso Miso Technique. Published in 1984, this manga is a sequel set two years after the 1982 manga やりすぎたイタズラ (A Prank Gone Too Far). At one point the story depicts the beating of one character's embarrassingly small penis with a shinai in order to (successfully) increase its size.