Koi to Summer Blend

High school boy Nanako decides to help out at “Nakatsuji,” a coffee shop run by his classmate's Nakatsuji's grandmother, for the duration of summer break.
Nanako had always found Nakatsuji — who seemed aloof and hard to approach — difficult to deal with, but as they spend more time together, he discovers a surprisingly caring and kind side to him, and he begins to have feelings for him.

I want to know more about him.

I want to be closer to him.

Before he knew it, Nakatsuji was all he could think about…?

(Source: Shinshokan, translated)

Note: Includes one extra chapter.