Deep Clear is a spin-off of both Kodocha, and Honey Bitter, both written by that same author, Miho Obana. This centers around Sana working as an actress in the future at age 26. Sana is working on a show that requires her to act as a detective, leading her to go the detective agency in Honey Bitter.
It's shown that Akito and Sana (now 26-years-old) are married and expecting their first child. However, Akito and Sana are experiencing some relationship problems--recently, Akito has recently left Sana, feeling that it's better if they divorce instead of raising the child together.
A pregnant-Sana asks Shuri for help on finding her husband, and it turns out that it's not that Akito doesn't want to raise a child with Sana--he's just really scared and worried that something might happen to her like what happened to his own mother.
When Sana gives birth, Shuri convinces Akito to face his fears by going to the hospital and seeing Sana and the baby. Sana gives birth to a daughter whom she names after Sari. After their daughter's birth, Sana and Akito reconcile and begin raising their daughter together.