Ane-san Countdown!

High school student Ritsuko Umekita does her best to stay under the radar of the scariest boy in her class, Saruwada-kun. Being from a long line of Yakuza, no one dares mess with him. Then one day her life is turned upside down by him. She is dragged home with him, only to find that…What's this? She has to marry him?! How will poor Ritsuko manage to escape the wolf's clutches?