Okan (オカン) is a female Justice Chojin from Kinnikuman Nisei ~All Chojin Dai Shingeki~ .
One of the few female chojin. Okay is nicknamed the Siberian Squall Mama. The defining traits of Okan is that she is a mother and wife first and foremost. Okan loses her first and only match, but continues to inspire Mantaro throughout the manga and acts as a mentor figure, as she provides advice and support from the ring-side.
The Top Chojin Contest occurs at Yokohama International Stadium, between the Justice Chojin and Evil Chojin.  Okan appears in the preliminary match, as greased-up monkey-bars appear and the chojin who can hold on the longest will be considered the victors.  After a male opponent tries to sabotage Fiona, Okan uses a daikon to attack her nearest opponent.  Okan is revealed to have won the preliminary match, which leads to her being entered in the main tournament. 
When the chojin are allowed to pick their opponents for their first matches, Okan picks Mantaro Kinniku.  The match takes place in the basement level of the Misetan Department Store, Shinjuku, Tokyo.  The only main characters in attendance - as audience members - are Rinko Nikaido and Ikemen Muscle. Okan initially misses her entrance on the escalator, as she is busy shopping for groceries. 
Okan is forbidden from bringing her basket into the ring, so she leaves it in her corner.  The match begins with a Palm Rush from Okan against Mantaro's face, followed by a series of Middle Kicks and a High Kick. It is revealed she is embarrassed when Mantaro witnesses her lower undergarments, and - sensing her embarrassment - he proceeds to grope her breasts to embarrass her further. He attempts a German Suplex, but Okan counters with a Forward Roll and an Ankle Hold. 
Okan follows with an Okan Sheets Ring. Mantaro is nearly about to give up the fight, when his back and legs are at risk of breaking, but an alarm clock falls from Okan's basket and Kinnikuman accidentally sets if off at 10am.  This triggers Okan to hang up her washing on a line at the side of the ring. Kinnikuman - trying to rectify his mistake - accidentally sets the 1pm alarm, which triggers Okan to perform her aerobics. Mantaro realises that the stereotype of all mothers being the same applies to Okan, and thus sets the clock to ring for 2pm, which triggers her into taking a nap: "the universal nap-time for mothers". 
Mantaro uses this opportunity to perform a Guillotine Drop.  He proceeds to throw her into the air, before he uses the Muscle Millennium to defeat her and end the match. The 3pm alarm rings, and Okan obediently obeys the alarm to pick her children up from school, with no animosity towards Mantaro or regret at losing the match, but does ask for a rematch when she "gets some time in [her] schedule". Okan leaves with her basket. 
Okan is next seen again at a supermarket. 
Okan is offered a selection of free samples, but soon eats them all in a single bite, and - after spotting Mantaro in disguise, trying to hide - pins him to a wall with the skewers upon which the samples came. Okan removes his disguise and holds him so that he cannot run away, and then asks him for help in picking ingredients for her stew.  Mantaro is surprised when she empties the cart and picks the dirty "bargain" vegetables.  After cleaning one off, she forces Mantaro to try a bite; to his surprise it tastes much better than the good-looking and clean vegetables. Okan says that this is a lesson true of wrestling. 
Mantaro may look rough, but he has pure and true talent, and The Doomman may look fancy and experienced, but he still lacks something at his core that makes him a true chojin. Okan reminds him that the important part about being a chojin is defending people from the forces of evil. This inspires Mantaro to change his ways and become a better chojin.  At the end of the tournament, Okan - along with the other Justice Chojin, including the new characters - join him as a large team and fight evil together. 
Okan Sheets Ring
- Okan clasps her opponents head with her feet in a Bridge move, then wrings them out
- Win/Loss Record (Single)
- X Mantaro Kinniku (Muscle Millennium)
- Submitted by: Tatsuya Fukuda (福田達也) of Hyogo
- Ends sentences with the word "munta"
|Kinnikuman, Terryman, Robin Mask, Warsman, Brocken Jr., Geronimo, Wolfman, Buffaloman|
|Mantaro Kinniku, Kevin Mask, Terry the Kid, Chaos Avenir, Gazelleman, Seiuchin|
|Bibimba, Jacqueline Muscle, Fiona, Okan, Sayuri Kinniku|