Kashidashi Tsuma, Marina no "Netorase" Houkoku Gaiden 2 -OL Marina no Doutei Choukyou-

After graduating, Marina starts working as an office clerk at a construction company. Around the same time, a new part-time employee, Tsutsujimori Shou, joins the team.
The two quickly grow close, and when Shou confides in her about his lack of confidence, feelings start to blossom between them. Before long, they’re in a relationship.
Marina, using the techniques she learned from her ex, takes the lead in teaching Shou, who’s still a virgin.
Sneaking around at work or meeting at hotels, the two grow more and more entangled. Marina finds herself drawn to Shou, who’s completely different from her ex.
Thanks to her “training,” Shou gradually gains confidence in himself. But… their relationship takes an unexpected turn.

[Translated from dlsite]