"As long as the age gap isn't more than 3, you are allowed to be."
Append this to the age is just a number thing. Also, no dirty stuff till the lowest number is 18. This clause was made for those who, upon turning 18 and their girlfriend/boyfriend being 16, aren't tossed in jail.
Imagine that...
わたし ほし
あなたわ あまい
Wa-Ta-Shi Ho-Shi
A-Na-Ta-Wa A-Ma-i
This is the limit of my current Japanese training.
When I finish, I will join the ranks of the Manga translators, and give back to this community.