The "That Time I Got Reincarnated as a Slime" spin-off 4-panel comic! Unlike the main story, it features a lot of Rimuru’s daily life! In volume 4, Rimuru becomes the homeroom teacher of five children in the Kingdom of Engrassia. As the seasons change, the days he spends with the children become irreplaceable.
- Diary 28: The Door to S Class
- Diary 29: Visitors To Tempest
- Diary 30: To Live In This World
- Diary 31: Midsummer Monster
- Diary 32: Sum-mer Va-ca-tion!
- Diary 33: A Certain Witch's End
- Diary 34: Camping Time!
- Diary 35: Just Getting Back
- Diary 36: Things I Want to Know, Want to Do, and Can Do
- Diary 37: A Eulogy for Heros