Anime is filled with fun tropes and memes. One that comes up in romantic comedy series is the 間接キス kansetsu kiss or “indirect kiss,” which is what happens when you drink from a can or straw after the person you’re in love with has put their lips on it. It’s something only elementary school kids would be silly enough to talk about in real life, yet the meme pops up in anime quite often. The Japanese way to find out if someone is running a fever is to touch foreheads with them (called odeko-touch), which is also seen in anime from time to time, usually with moe-tastic results. Sometimes the meaning of these jokes can be difficult for us to understand culturally, like the tendency for a sleeping character to be drawn with a snot bubble growing out of their nose. One decades-old visual gag in anime and manga is to draw a character with a flower growing out of their head, which represents aho (ah-ho), Osaka-ben for “stupid” — essentially, the character is so dumb their brain is made of dirt, hence a flower can grow there. The bird often seen on Yuko’s head in Nichijou is a variation of this joke.
Odeko-touch is how you check for a fever in Japan.
