"Let's Go Surfing!!" is the first episode of the Wave!! anime.
Masaki is a middle school student living in Oarai. One morning, while walking his corgi, he spots Sho surfing. He is so fascinated with it, he can't seem to get it off his mind. Next day is the first day of school after summer break and Sho is the new transfer student. After classes that day, while Nalu sings while playing his ukelele, Sho overhears it and uses this chance to introduce himself to Masaki and Nalu.
Nalu and Masaki take Sho to the local surf shop and show him around. Masaki never had an interest in surfing before, the sudden change in behavior is surprising to Nalu. Masaki can't swim, so Nalu determined he wouldn't want to participate. When Sho offers to teach Masaki, Masaki eagerly agrees.
The next day is the first day that Masaki goes to practice with Sho and Nalu. Sakura, Masaki's little sister, ends up following Masaki to the beach to see what he is up to. Sho gives basic tips to Masaki on how to paddle on a board and how he stands up on it, but Nalu reminds Masaki that standing on a board takes a lot of practice and that he will fall in the water if he rushes. Sho shares that he learned to surf from his brother and he used to fall in the water a lot trying to stand on the board for the first time.
At dusk, they all three paddle out with Masaki for the first time and reach a wave. They encourage Masaki to paddle through it, not expecting him to not stand. He surprises them and himself by standing and managing to ride it for a few moments before falling in. They rush over to make sure he is alright, only to find him ecstatic over his first wave.