Kamatte Shinsotsu-chan ga Maikai Sasotte Kuru: Nee Senpai, Shigoto mo Koi mo Kyouiku Shite Moratte Ii desu ka?

Masato Kazama is 26 years old. He is a salaryman working at a high pressure company... an advertising agency. He is what you would call a "corporate drone."

Masato's junior, the new-graduated employee Nagisa Inami, is the perfect heroine.
She is beautiful, stylish, and is quick to learn her job. In addition, she is friendly and sociable.
If there is one drawback to Nagisa, it is that she likes her trainer, Masato, a little too much.

"Hehehe~ I can give him a kiss whenever he compliments me, right?"
"Let's go for a drink today, senpai!"
"That's right. Let's go have a drink today, too! You say you can't drink with a pretty junior?"

She always invites me out for drinks after work, and when she gets drunk, she becomes a spoiled brat.

"If we miss the last train, let's just go to a hotel! I'm sure you know what that means............." What?

Is it because she loves to drink, or because she has trouble getting home, or is it just youthful indiscretion?
Or could it be......?

(Source: Fantasia Bunko, translated)