Shin Chimoguri Ringo to Kingyobachi Otoko

The "goldfish bowl man" is a man whose head is a goldfish bowl. When he sucks your blood, you turn into a goldfish. In order to stop him, Ringo, a.k.a. "Blood Diver" wearing his school swimsuit, and Haosuke, an ordinary high school student, take action. (Source: Earth Star Comics, translated) Note: