He is the demon-like leader of the Brutal Chojin faction within the dMp and the co-founder of the d.M.p. He and Qilinman were taking some of Sunshine's students to add to theirs. They were destroyed when Sunshine blew up their headquarters.
Shimao, althought unnamed, appears in a couple of pannels, usually with his d.m.P comrades, terrorizing and killing people. Then, he, Qilinman, and a couple other d.m.P members were watching how the Justice Chojin plan to re-open the Hercules Factory, making them laught.
Qilinman and Shimao shows up on a screen after Check Mate's defeat, after which they send a giant spear down to impale Sunshine, before mocking his plans of overthrowing them. The d.m.P members start to fight with each other, and two of them charge towards Shimao and Qilinman, who literary smash their heads (reference needed). But before they could react, the whole d.m.P base started to fall apart, killing them and the destroying the evil organization (reference needed).
Shimao resides in the "Demon Hand" on Mount Fuji, which serves as the headquarters of the DMp.  He - along with Sunshine and Qilinman - kidnap three of the new generation of Justice Chojin: Gazelleman, Terry the Kid, and Mantaro Kinniku. They reveal that they have kidnapped Meat Alexandria, and the only way to rescue him is to go deep into the Hand and compete in their tournament against their strongest chojin. 
Once the New Generation win the tournament, Shimao and Qilinman lure them into a room where Meat appears to be dangling from a rope.  They explode what is revealed to be a puppet, before revealing Meat is tied up by a rope connected to a giant stone fist (complete with a sharp arrow) that will kill Meat if the ropes are tampered. After Meat is rescued by Checkmate, Shimao and Qilinman escape in an ejection pod and explode their base. 
They proceed to kidnap Jade, Bath the Shower, and Captain Macko from the Hercules Factory.  The New Generation find them in the crater of Mount Aso, where a new tournament is prepared.  The two take VIP seats to watch the following matches.  When it is revealed Jade and the others weren't properly brainwashed, and still good, which leads to the victory of the New Generation, Shimao and Kirinman express dismay.  They are then captured by Kevin Mask, who randomly appears, and are taken to Chojin Prison. 
Win/Loss Record (Single)
- X Kevin Mask (Sleeper Hold) (V-Jump)
- Submitted by: Daisuke Kuboi (久保井大輔) of Hiroshima as Shimaō (死魔王 Death Devil)
- He first appears as a fan submission on the cover art for chapter 374 of the original Kinnikuman.