Shouta Takeuchi has been diagnosed with asthma since he was a child, causing him to frequently miss school when he is hospitalized. He resents the fact that he cannot experience a normal academic life and avoids attending classes, even when he is feeling well. He doesn't see a need for friendship until he meets Youhei "Macchan" Matsuki, who approaches him one day. Gradually, their interactions make Take look forward to spending time with Macchan, and he starts to realize that he may be romantically interested in him.
As Take and Macchan become closer, their relationship is noticed by their mutual schoolmate Haruko "Umeko" Umezawa. Both their mothers task Umeko with looking after Take, but she only considers him a childhood friend due to their circumstances. However, when Take is with Macchan, Umeko sees a different side of him that she usually doesn't see. She becomes attracted to Macchan as well after witnessing his kindness to Take.
Despite their mutual attraction to Macchan, Take and Umeko acknowledge each other as rivals for his heart. However, this only strengthens their bond. As time goes by, they never act on their feelings but they have no regrets about falling in love with the same person.
