I was an episode behind.

Episode 8:
Ending eyecatch: Sano Toshihide drawing Keima's mom... Holy. Shit. I can't imagine a more ideal galge artist-TWGOK character combination. I recognized it instantly, even without the signature at the bottom.

Episode 9:

Elsie and her newfound love for fire trucks. All else is secondary.

Like RZ said, Shiori is a very focused kind of librarian girl. They are indeed very common. Shiori gets bonus points for being so shy and introverted that the majority of her "dialogue" is internal. She puts all other shy librarian types to shame.