This was a childrens magazine by Shogakukan. Stories featuring the 3-2 Class Mates ran in 1986 and 1987. Issues I know that contain stories are listed below, but there are most likely more out there.

 

April 1986

May 1986

 

August 1986

October 1986

November 1986. Contains the story Chem Gets Involved, Good Luck With The Big Sports Day (チェムがかつやくガンバレ大運動会)

 

April 1987

May 1987

June 1987

July 1987

October 1987

November 1987