Trying to find anime name
I only know a few things from its first episode and then maybe another episode
I believe it was made maybe in the 90s or 80s
It's set in Modern Japan
I know the main protagonist is a girl, maybe 15-18? , she had brown hair and she wore a sailor like school uniform. And she lived in a house with I think was her grandmother or grandfather,(I'm not sure if the girls parents were alive but her mother might have been a news anchor,) the girl herself is just a normal teenage girl, I don't think she has any powers, i also know that two of the supporting characters were a male maybe around the same age as her, and I think the other was his little brother, because he rode around on a small big wheel trike and whined alot.
(I think they find some relic that ties with some bad people, but I'm not 100% if that's the plot)
I don't remember who was the main antagonist but in one of the episodes they were getting chased by a man wearing all black on a motorcycle, I think he was just a minor antagonist.