Japanese System of Honor and Saving Face?

Question:

What are the basic rules for the Japanese system of honor. I once saw an anime where a guy and a girl got into a motorcycle accident, and the school wanted to kick the boy out for being so reckless. I didn't really understand it. But it's not just that example, I want to know in a more general sense. Like if a boy asks a girl on a date how does she politely refuse?
Also are there a set of rules for this and what are they called?

Answer:

It is called Seken-Tei (世間体), which means the image in the eye of the public.
Japanese people tend to exclude anomalies from their groups, so they often worry about Seken-Tei.
Many people try to avoid troubles because they then become these anomalies. Kotonakare-shugi (事なかれ主義) is a policy where people highly value a decision of trouble avoidance and I think is widely seen among politicians. I think this is why Japanese politics are always too late to avoid troubles. People sometimes say it is bad for Seken-Tei (bad in public view) while making a decision. Many people worry about name values of their jobs, companies, and graduated universities, checking other people's status. It is because we are a homogeneous culture that has required conformity to a single view that we have rather a simplistic social evaluation measurement and we try to avoid inferiority in its measurement. Inferiority, too, can be an anomaly that can cause a person to be expelled from a social circle. Also, many people do not assert themselves, because strong assertion may cause them to be seen as trouble makers. "Sekentei-ni warui" (世間体に悪い) is a phrase that you may hear in Japan which means, this is bad for in public view. Save facing mentality may be strong in middle aged men. My manager at the office told me the men in 40s worry particularly of their images.