@FredFriendly
It was 2 years from the accident. The accident happen at the late 3rd year of Nasa junior high and he's on the coma for 4 months which makes him miss his high school entrance ceremony, which happen at April. Then he have his entrance exam one year late and then doing all sorts of job for one year before meet Tsukasa again, which is at his birthday. One thing to note, this is when Aya is supposely is at her third year of high school so there you go.