Quite an interesting topic and the characters don't seem bad. I wouldn't really know what to expect, but the MC's reactions are realistic enough for me, for a manga. I don't like how scripted this feels otherwise. The bag decorations getting stuck, creating that encounter, was legit, naturally, but the super fast confession, and especially the deus ex brat pushing the girl so hard out of nowhere are really stretching my suspension of disbelief. It feels unnecessary. Almost something you'd find in a oneshot, to make the whole story fit in a single chapter. Of course such hypersonic confessions do exist, but why was it necessary here? The MC is deadly afraid of physical contact with women, so a really aggressive girl might not be the best thing for him.