Miu-chan no Hanaji

High school girl Sawa Misumi harbors a secret she can tell no one: she gets excited whenever her best friend, Miu-chan, gets a nosebleed. Because Miu-chan is naturally prone to nosebleeds, Sawa has been secretly enjoying this aspect of their daily lives. However, one day, Miu's nosebleeds suddenly stop completely. Desperate to get her bleeding again, Sawa goes to great lengths to make it happen, but as her desires escalate, she ends up causing an irreversible incident...!

(Source: MangaDex)