When Merfolk Take the Swimming World by Storm

[Updated according to the rankings. Updates at 23:00.] The merfolk Yu Yu happened upon a mysterious whirlpool on the ocean floor. After accidentally being sucked in, he discovered that he had become a human baby with legs. Most children say "Mama" or "Dada" as their first word. Little Yu Yu's first word was: "Water!" Who could understand how cruel it was for a merfolk to be trapped in a baby's body for years, unable to swim? After wishing on every star in the sky, Yu Yu's parents finally took their son to the swimming pool for lessons. Who could have guessed that the moment he hit the water, their child would shoot forward so fast that even the coach, holding a float beside him, was left dumbfounded? From then on, the swimming world had a new demon king. Yu Yu's freestyle swept from kindergarten all the way to the Olympic Games. He was unmatched, and the media hailed him as China's shining star of the sea. Though he achieved dazzling results and broke countless records, Yu Yu became famous for a rather bizarre reason. After Yu Yu won yet another Olympic gold medal in a different event, reporters swarmed him for interviews. When the Olympic champion opened his mouth, his shark-like teeth, straight out of a cartoon, nearly blinded them. Yu Yu: "Oh, you mean why? Because I think Matsuoka Rin is really handsome!" Media: ? Opponent: "I don't know, either. He shouted something about a shockwave and swam off. Is that the secret of an Olympic champion?" Media: Huh? Childhood friend: "You'll get used to it. He's just a chuunibyou." [Reader's Guide: 1. A merfolk becomes human. He's not actually a fish. 2. Everyone's relationship is platonic. His childhood friend is a mother hen. 3. All competition records are fictional. 4. There may be some esports plotlines involving his childhood friend.] Theme: Hard work pays off