Am I Wrong to Look Forward to Falling in Love in the Blue Sea?

Pure daily life + combat + slight magic modification + maybe a female protagonist? Yamaguchi Hakaki, who grew up in China, returned to Japan due to family reasons and was admitted to Izu University. As a single mother, he decided to take back everything he had in college, and his imaginary college life was about to begin, until he walked into a diving shop called "Grand Blue". (Don't underestimate the bond of pure love party!)