Gomen, Nanami-kun to wa Tsukiaenai

During the spring break of his second year of high school, Mutsuki is confessed to by Nanami, whom she has always liked. However, right after that, Nanami gets into an accident. The moment she fervently wishes, "I don't care if I die in your place, please don't take Nanami away...!", she wakes up to find himself back on the first day of her second year...! Then, the mysterious Grim Reaper tells her that the condition for saving Nanami is "to repeat her second year of high school without Nanami confessing his love to her"!? An unwanted love fight begins as Mutsuki continues to avoid the confession from the person she has mutual feelings for!

(Source: Comic Days, translated)