Complex sentence: Yukinari Sasaki is an average high school student who was teased and bullied by girls to the point that he developed an allergic reaction, breaking out in hives whenever he comes into contact with a female.
Split into simpler sentences: Yukinari Sasaki is an average high school student who was teased and bullied by girls to the point that he developed an allergic reaction. He breaks out in hives whenever he comes into contact with a female.