Don't Toy With Me, Miss Nagatoro, volume 20

Now officially a couple, there is only one challenge Nagatoro and Senpai have left to conquer: their first k-k-kiss! But even the honeymoon phase of new love can be fraught with friction, and soon Senpai makes a mistake so big, it leaves Nagatoro in tears and their relationship hanging by a thread. With entrance exams and all sorts of new anxieties looming, can they patch things up before graduation parts them for good?