About a year ago, the body of the female victim was found in some mountains near Hitoyoshi:

“The Kumamoto Prefectural Police have set up a team to look into the case, suspecting it is that of Mayuko Arakawa, 17, who was reportedly killed and whose body was abandoned in the mountains, they said Sunday.”

http://www.japantimes.co.jp/news/2014/06/09/national/crime-legal/body-found-rural-kumamoto-believed-missing-teen-girl/#.VdglnbSyty7

According to this article, the murderer was given a sentence of 18 years for the crime:

“Akaishi received an 18-year prison sentence for murdering a third-year high school [student].”

Personally, I’m not in favor of the death penalty but 18 years strikes me as light punishment for the murder of a young person with a lifetime ahead of her.

http://www.tokyoreporter.com/2015/08/22/kumamoto-inmate-commits-suicide-with-underwear/