The age of consent is 13, but that is national. Each prefecture also has their own age of consent and all are set at 18. So, the national government can not punish someone for having sex with a 14 year old, but the prefectural government can. Only if the child is below 13 can a person be prosecuted by both the prefectural and national government. It basically acts as a safety net and a double punishment for those who prey on preteens. See?
How old are they again? lol