This man-chest mouse pad is probably going to cost you a few hundred bucks lol~
Exclusive to ani-mu-mo store when you buy all volumes of the Assassination Classroom (暗殺教室 Ansatsu Kyoushitsu) anime DVD/Bluray… although it wasn’t stated if you must buy the regular edition or limited-edition discs, at at least 5,000 Yen a pop, they aren’t going to be cheap.
Shop link: http://shop.mu-mo.net/avx/sv/list2?jsiteid=ANMS&categ_id=3001802
If you can’t afford all that moo-la (like me) to buy all the discs, I suggest looking out at the aftermarket for 烏間先生胸板マウスパッド and keep your fingers crossed that he pops up at a more affordable price.
Ani-mu-mo tokuten news! Newly illustrated Karasuma-sensei chest mousepad special freebie is completed! What do you think, everybody? Do (get your hands on the mousepad) try to feel the actual item if you can! アニミュゥモ特典情報！全巻購入特典の描き下ろし烏間先生 胸板マウスパッドがついに完成！！いかがでしょうか、皆様。この烏間先生の胸板…ぜひ生で感じてみてください！
About the manga/anime:
Assassination Classroom (暗殺教室 Ansatsu Kyoushitsu) is an ongoing Japanese manga written and illustrated by Yuusei Matsui that has appeared in Shueisha’s Weekly Shounen Jump magazine since July 2012.
A strange new teacher is introduced to Class 3-E at Kunugigaoka Junior High School. The teacher is a round-headed, tentacled octopoid creature capable of moving at speeds of up to Mach 20 and whose color changes depending on his mood. Prior to introducing himself to his new class, he managed to carve out a large chunk of the moon to become a permanent crescent moon. In a year, he plots to destroy the earth, but decides to teach a junior high school class in the meantime for an unknown reason. With this strange creature having effectively taken over the world, the government reluctantly complies with his request on the condition that he does not harm his students.
Affectionately, the students of Class E call him Korosensei, which is pun on the term korosenai (殺せない lit. unkillable or can’t be killed) and sensei (先生). These same students greet him everyday with assassination attempts in their journey to save the world by eventually murdering their own teacher, and to earn 10 billion yen from the government.