Anything Sakuma Ryuichi does when he's in Keet mode.
Ryuichi (hiding under Touma's desk and holding up his stuffed bear): MR. BEAR SAYS SLEEPY SLEEPY TOUMA!
Reiji chasing Shuichi, Sakuma, and K in the middle of Manhattan in her gigantic robot-panda.
K's solution to cure Shuichi when he goes mute. He sticks a live grenade on his head. In fact, any time K interrupts anybody by producing a rifle out of nowhere is gold.
Shuichi in a banana suit.
What he says while wearing that banana suit:
Shuichi: I CAN'T WORK WITH HIRO ANYMORE! HE'S GONE BANANAS!!!
In the final volume, K gets the brilliant idea that Bad Luck needs to interrupt a Nittle Grasper concert to prevent them from releasing their newest song. To avoid being recognized, he has the bandmates dress in disguise—Shuichi is an angel riding a pony, Hiro is a schoolgirl with two pigtails, Suguru is Godzilla, and K himself is a giant kitty. Naturally, their outlandish disguises makes everybody recognize them immediately.
Then to interrupt the concert, K kicks Shuichi and Suguru onstage. Shuichi at this point is competing against Nittle Grasper for song releases and they haven't finished a song. So Shuichi frantically starts writing a song right in the middle of the stage, Hiro nonchalantly jams on his guitar for the fans, and Suguru tries to deny himself of any responsibility to Tohma, as the man and the rest of Nittle Grasper stand there dumbfounded.
K threatens Yuki to treat Shuichi right so Shuichi can write songs, and then he later follows up with his threats by sniper-shooting at Yuki in his apartment when the other man is mean to Shuichi. With each shot fired that narrowly misses Yuki, Yuki abruptly gives Shuichi a hug and starts sweet-talking him.