A male employee is suing sportswear maker Asics Corp. for alleged mistreatment after taking paternity leave, a case that has cast a spotlight on gender equality and workers' rights in Japan.

The lawsuit — filed by a 38-year-old man who says he was harassed by his employer after taking parental leave in 2015 and 2018 that is legally available to all workers but rarely used by men — began at a Tokyo court last Thursday.

Asics denies the allegations.