“High School Boys and Tricks” is the 89th chapter of the manga.
Motoharu and Mitsuo are walking home at night, when Mitsuo offers Motoharu a piece of gum. He accepts and is about to take it, before pausing. He wonders if it could be the type of popular prank that involved something snapping around one’s figure upon taking the gum. In typical fashion, he decides to go along with it for Mitsuo’s sake.
Motoharu bravely grabs the gum and pulls it out. Much to his surprise, it’s an ordinary piece and he eats it, thanking Mitsuo. Mitsuo then says his hand would probably be smelling of lemons by then. Hearing this, Motoharu tenses up. He recognizes it to be the setup for another prank in which the victim sniffs his hand and the prankster gives him a blow in the face.
Despite the danger involved, he resolves to play along and sniffs his hand. It turns out that it really smells of lemons, stunning him. After a brief silence, Mitsuo asks him to say “deer” 10 times. Motoharu realizes what this trick is supposed to be and acts unaware. After he says his part, Mitsuo asks him what Santa Claus rides. Motoharu blurts out ‘reindeer’.
Mitsuo praises him for getting the answer right, leaving Motoharu dumbfounded. He wonders why he doesn’t know that the answer is ‘sleigh’. Mitsuo then asks him if there were more uphill or downhill slopes in Japan, to which he immediately answers ‘downhill’.
Mitsuo begins to wonder, seeming unsure about the answer himself. Motoharu is astounded that the question was posed as a quiz and not a trick question. Thinking to himself that Mitsuo doesn’t understand how pranks work, he becomes determined to show him. Taking out a packet of gum strips, he offers him one.
He gladly accepts, taking a piece, when a cockroach crawls from the packet on to his hand. He yells in sheer horror. Motoharu then takes off the roach, revealing it to be a dud as he tells Mitsuo he got him pranked.
For a while, Mitsuo bows his head in grim silence. Looking up, teary-eyed, he curses Motoharu before running off and leaving him behind. A slightly embarrassed, apologetic Motoharu stares after him, realising that playing pranks was a mean thing to do.
In order of appearance: