Lol yeah it's a guest comic by BL author Yamada Yugi. In the afterword Gouda writes about how he was stoked to find out people were making Mori no Asagao BL doujinshi
I changed opinion from my last comment a bit, here's my over-analysis for anyone interested:
The breakup with Asami probably lead Naoki to seek emotional refuge in Watase since he had no other outlet, but Naoki is so invested in Watase because it's implied Watase's the reason he became a...
Maybe the consequence of originally being serialized in a magazine. The huge amount of flashbacks are the worst part of it for me lol. The author's independently published works have much better pacing.
Lol I checked the raws and it looks like a mistranslation.
On pg 136, panel 1 Asami should be saying something like "Your family's chicken coop burned down and you've been bringing this guy flowers".
And pg 137, panel 1 should be "I find it hard to believe you'd bring flowers for the man...