A 69-year-old man in western Japan filed a lawsuit Thursday seeking assets left behind by his deceased same-sex partner and damages for being barred from attending his cremation.

The rare case involving inheritance from a same-sex partner highlights the problems faced by such couples upon the death of their partners in a country that only provides legal protection to married couples.

The man from Osaka Prefecture sued his partner's sister at the Osaka District Court, seeking to win back the assets held by her following her brother's death in March 2016.

The man is also seeking 7 million yen ($64,000) in damages from the woman, saying he was robbed of the chance to arrange the funeral for his long-time partner due to discrimination against homosexual people.

"I am dissatisfied that I am not legally protected on the grounds that we were a same-sex couple," said the man, adding he hopes such discrimination will be eliminated soon.

While there have been cases of same-sex couples filing lawsuits to seek the same rights granted to opposite-sex married couples, a lawsuit over inheritance rights is rare, according to the man's lawyer.

So far, Japan's top court has not recognized the inheritance rights of same-sex couples or opposite-sex couples under common law marriage.

Seven municipalities in the country recognize partnerships of lesbian, gay, bisexual and transgender couples, though their recognition does not entail legal rights or obligations such as marriage under the civil law.

The man in the latest suit said he started to live with his partner from around 1971 and they lived mostly off the money the plaintiff made through his work.

The woman knew they were living together, and the man had attended weddings and other ceremonial events involving his partner's relatives, he said.

But all of that changed when the partner died at 75. The woman did not allow the man to attend his partner's cremation and only allowed him to attend the funeral as a visitor not a family member.

The woman also closed the business managed by the partner and terminated an office lease contract without the plaintiff's consent, while the assets held by the partner automatically went to the woman.

The man claims he and his partner had agreed they would inherit one another's assets in the event of death but said he was told by the lawyer representing the woman that he had "absolutely no rights."

"There seems to be discrimination against homosexual people even before the legal hurdles," said Lawyer Kazuyuki Minami representing the man.

"If a same-sex marriage system is established, it would not only ensure the rights of partners but also help resolve irrational discrimination," said Minami.