Male fertility clinic to go alone?

Posting from new account to avoid friends finding out.

I’m looking for a male fertility clinic that I can go there alone without having to inform/bring my partner.
All the clinics I found were focus towards women and only had men as something additional to check, but I’d like to get myself tested without my partner.

Ideally on the denentoshi line (tokyo/kanagawa) but i don’t mind 1h commute as long as it’s once only.

I’m not fluent in Japanese but can manage my daily life stuff, as long as i get my result with ok or not ok then I’m fine, can use Google translate on the result document to figure out the rest.

Also, is this kind of tests covered by the national health insurance?