Admiral Shimaru is a master of kenbonshoku haki and the eater of the Tsuma Tsuma no mi, he wears sunglasses to shield his eyes because of his excessive kenbonshoku haki training, his sclera is black and his iris is white, his kenbonshoku haki is able to predict up to 5 minutes in the future and can not break until he blinks, which is why he wears sunglasses, the longest he kept his eyes open was 4 hours when he was battling Rocks D. Xebec he wears a marine admiral coat and white shirt and black pants with black shoes.
Maemoto surprises Rocks as he lights up the lantern
His Imagery of justice is called "Barren Justice" as he thinks justice is an empty shell and needs to be filled, he tries to "fill" the barren meaning of justice by travelling places and slaughtering all the pirates along the way.
He meets with Gol D. Roger when his ship was chasing Roger to little did he know, the knock up stream, roger ultimately got away from Admiral Shimaru and his ship was badly damaged.
He chases after Rocks D. Xebec to an uncharted island, Shimaru had defeated Rocks' Crew a battle between them lengthening up to 4 hours, when Shimaru corners Rocks as Rocks pleads for his life, Shimaru blinked after 4 hours because of a surprise attack from Rocks' crew, the mission of capturing Rocks D. Xebec was ultimately passed onto Garp.
A few months later he meets Garp and gives a disgusted look to him as Garp just caught Rocks D. Xebec with the help of Gol D. Roger.
He then searched for Laugh Tale (Raftel) because he had heard of an island at the end of the grand line after it was discovered by Roger, this voyage made him miss the capture and execution of Gol D. Roger, a few months after he passed the last island before laugh tale (Raftel) his ship faced an enormous storm, the ship returned to marineford near scuttled, only a few of the crew were left and Admiral Shimaru was nowhere to be found.
As of now his status is unkown