A man who was driven by jealousy to repeatedly threaten the author of a popular teen manga series was sentenced to 4? years in prison by the Tokyo District Court on Thursday.

Hirofumi Watanabe intended to severely disrupt the business of Tadatoshi Fujimaki, the author of ¡°Kuroko no Basuke¡± (¡°Kuroko¡¯s Basketball¡°), with the threats, which lasted over a year beginning in October 2012, the ruling said.

Watanabe, a 36-year-old temp worker, sent death threats to organizers of several manga festivals in late 2012, demanding they cancel stage shows featuring Fujimaki¡¯s work and remove related merchandise.

In October 2013, Watanabe sent a letter to Seven-Eleven Japan Co., claiming he poisoned various snacks with Fujimaki¡¯s manga characters on their packaging. The convenience store pulled the snacks.

Presiding Judge Iwao Maeda said Watanabe deserved no leniency, given that he ¡°carried out all these business obstructions solely for the purpose of venting his jealousy.¡±

In explaining why he handed down the stiffest sentence possible, Maeda said: ¡°The defendant carried (the threats) out over and over again for extremely selfish reasons. In this regard, the gravity of his sin is incomparable to that of preceding criminals of a similar kind.¡±

Maeda also slammed Watanabe¡¯s lack of remorse, noting he boasted that he would never feel sorry for his actions.

Watanabe said in his opening statement in March that he made the threats as he was jealous of Fujimaki, whose success as a manga author and academic made him feel unbearably bad about his own life.

Watanabe characterized himself as an ¡°underdog¡± who was abused by his parents and bullied at school. He said he was gay and had never married or had sex his whole life, and felt ashamed of his low-paying job, which earned him less than ?2 million annually.

Having struggled with suicidal thoughts most of his life, Watanabe said: ¡°I thought that if I somehow managed to harass and depress (Fujimaki), I could drag him into my suicidal journey.¡± He then swore to hang himself once released from prison