The Tsuchiura branch of the Mito District Court on Friday sentenced a 19-year-old boy to a prison term of between five and eight years for killing a housewife he met through a mobile phone dating service Web site.
According to the ruling, the youth, whose name was withheld because he is a minor, fatally stabbed Kaori Watanabe, 28, with a kitchen knife in a car at a parking lot in front of her apartment in Ushiku, Ibaraki Prefecture, on April 23.
Prosecutors had sought a term of between five and 10 years.
The boy, who is from Hokkaido, met the housewife through the dating service last year when he was a high school student. He moved to Ibaraki Prefecture in March after graduating.
According to the prosecutors, the youth had originally believed Watanabe was divorced and killed her after she refused to live with him.
Although Judge Kazunobu Yamazaki said the youth was self-centered and self-righteous, he also partially acknowledged his lawyers' argument that the victim deserves some blame because he had felt betrayed after learning she was not single.