Sabusuku Ikemen no Renai Shidou Dousei Tsuki tte Kiitemasen - Vol. 1 Ch. 6

[MangaDex]

 

[lemon-dono]

Him being roofied in the past would tie-in to him not accepting food or gifts from people (other than anzu)

 

[Himatsubushi]

Also the unknown thing at the end was just messy handwriting for 担当 (in charge) so 担当U is their editor I think.