Eren and Levi are happily married, raising their child, Riren.
Riren is 4 years old, attending Maria Scouts Kindergarten. Everyday he comes home hungry, even though he goes to school with lunch. Everyday he comes home cold, even though he goes to school with a jacket.
Eren and Levi start to get worried, wondering what is happening to their little munchkin at school.
One day, Eren and Levi go to Riren's school to check on him, only to find that nothing is wrong. Nothing, except Riren has met another boy, who Eren and Levi have happened to see wearing Riren's jacket, and eating his lunch.