Ring X Mama

Everything About Fiction You Never Wanted to Know.
Sanae "Justice Asuka" Takamori, the main female character.

Ring X Mama (リン×ママ, also romanized as Rin x Mama) is an Ecchi manga by Johji Manabe that starts with a female wrestling otaku named Hamazaki Ryoma watching a match with his favorite retired female wrestler ("Justice Asuka") in his apartment while busily enjoying himself.

And that's when his landlord Takamori Sanae stops by to drop off a package.

After a weak attempt at hiding what he was doing fails miserably, she discovers his female wrestling shrine to Justice Asuka, and to his surprise, she's actually rather interested in his obsession, and he notices she bears a resemblance to Asuka, but writes it off as a coincidence.

Sanae decides to needle him about his date with rosie palms, which quickly leads to her putting the moves on a very surprised Ryoma, and and he gets to enjoy a lot more than his right hand with his landlord.

After sleeping off their exertions, Sanae answers the door, and Ryoma is shocked to see Violence Rose (another former member of Gigamax, Justice Asuka's old promotion) is apparently friends with his landlord, and he realizes just who he slept with.....

The rest of the manga has Ryoma become the manger of the newly reformed Gigamax, has him involved in a lot harem antics with Sanae and a lot of other female wrestlers, and he learns why Gigamax broke up a few years ago.

The manga was originally scanlated to English by the scanlation group Soba Scans, who soon withdrew it from circulation on their website once they accepted an offer to translate manga professionally, and they have already helped release the official version of volume one to English, with the others on the way, though their unofficial translation can still be easily found around the internet on various scanlation sites.

Tropes used in Ring X Mama include: