Warau Ishi

Ataru Natsumeda is a withdrawn first year in high school, unable to rise above mediocrity. His parents are on bad terms with each other, so Ataru leads a lonely, gloomy life. His sister Tsukimi is endowed with both wit and beauty, which causes Ataru to have a severe inferiority complex. One day, Ataru gets bullied again by delinquents who are after his beautiful sister. His classmate Nirasaki witnesses this, and asks Ataru, "Why didn't you just tell them to piss off and die?" Soon after, she passes the mysterious "wishing stone" to Ataru with a kiss, as if she's restraining him from asking any further questions. Rumor has it that this "wishing stone" can make any wish come true!

Having obtained this stone, Ataru wishes for the delinquents to die! And within a moment, the three delinquents die bizarre deaths!! What is this "wishing stone"...? Who is Nirasaki...? And what will be the fate of Ataru Natsumeda, who has set foot into this horrible world...?!

(Source: Café con Lenin Scanlations)