One of the major settings of the show is a hotspring, and on several occasions naked butts are breifly shown.
A girl repeatedly gets nosebleeds to show that she's aroused by other male characters.
A character asks another if she is horny because she has just broken up with her boyfriend.
One main character gets drunk and it is implied that he strips down. Later, another character posts picture online of him shirtless and pinning another against the wall in an attempt to kiss him.
One character is thought to have "sex appeal"
One man mentions pole-dancing
There are a couple comedic PG-13 sex jokes but nothing major. It is very mild.
Multiple men are seen bathing together in a traditional Japanese hotspring. This is not at all sexual.
The main character is seen lying in bed in only his boxers. Later another man is seen lying on top of him. This is for comedic effect.
The main character claims that another man's performance has so much eros it could "impregnate" him. This is for comedic effect.
The main character is groped by another competitor, though it's done in a teasing manner.
Often, the main characters perform in form fitting costumes as it is figure skating.
A man runs into another man's room, and jumps on him. This is for comedic effect.