Identifying an anime

[Ebarre]

I need help identifying an anime please... Fair warning, my wife thinks I'm insane, but I swear I remember this...

The series starts with a guy investigating like a shrine thing his grandpa (I think... Maybe great grandpa or something) had built. There's I think a sword in there, and he ends up releasing and interacting with a demon... Witch... Thing? That his ancestor had sealed away. She gets her power from these like gem things, and she convinces him to give her one of those gem things for some reason and breaks whatever spell or what not had her captive. She's not like super evil, more mischievous as the series progresses.

I know that is really kind of vague, but I'm struggling to remember specifics. And it's driving me insane not being able to find it, I've been searching for literal weeks 😂

[Finfan]

Tenchi Muyo! Ryo Ohki. I've just been watching these.

[Clayton_n]

For the record Ryoko gets him

Also Tenchi si based on I Dream of jeanie