Why is it in almost every anime when there is a male main character, Everytime a female main character comes on to him he gets all flustered, scared, or runs away? I mean through a whole series we see tons of huge boobs, panty shots, etc. But when a hot girl or mainly the love interest, tries to hold hands with the guy or kiss or anything of that nature. He always chickens out, or thinks that it's inappropriate or they are interrupted or he's to stupid to get the situation. They can fight monsters and demons but when can't do that? It won't make the character any less Noble. Any why is there the need to ALWAYS have other characters interrupt it or make him to dense to understand the female loves him. Why can't anime creators for once let romance start near the beginning and go smooth instead of towards the end and super hard to get to? It's been this way since anime first started and it's not funny or entertaining anymore.
I talked about this a little bit with my friends at school. One of them said to me that showing public affection is considered rude or embarrassing in Japan. So this is the reason why some couples are hesitant to hold hands at first. One example can be found in Clannad: The couple once walks to school alone. One of them suggests, embarrassed, to hold hands. The other person replies "But what if someone sees us?" They are close to finally holding hands but they get interrupted by a friend.
But this is probably only one of many reasons why this happens. A guess of me would be writer laziness. But I wouldn't take my word for it.
I read this question then I can know you have watched Anime and Drama from others country did you? Most of this same story is come from same company, I watched many these kind of same story because I lazy to search anime, most of time I searched using keyword by company name. They are the same company's anime, most of them story look like this. This is the first point. The second point is their ways of thinking, cultures, their life, their research, rules, inspire make them having story inspiration look like this.