
Pedo-alert!
Remember, there's a 9-10 years difference!
Age 18-19 seems appropriate!
Ren still has 3-4 years to go!

It depends on where in Japan exactly. It actually ranges from 13 to 17 years old. In most urban places it's going to be about 17.
Besides, when it comes to that, it's only legal for a certain age gap, regardless of the legal age. Here in Canada, the age of consent is 12 as long as the other person is no more than 2 years older. If not, the actual age of consent is 16.

If I recall, it's 16 but people prefer to do the deed with their older partner after high school. (Around 17-19 years old, preferrably 19 since it's considered as being an adult in Japan.)
I guess it really depends on the their relationship and preferences.
Dannng. Ren gave head. Wuh. Mindblown. In other news, I'm kinda annoyed Haru still treats Ren like he's a child. The guys 16 for God's sake. He can't hide behind the excuse of Ren being too young for long. I wonder if Haru realizes how confusing he could be. Does he want Ren or not? :/