Two months after moving to Tamagi, Masaki must deal with the consequences of his spur of the moment decision to enter into a Love Triangle as the circle of friends prepares to welcome the new year.
Harvest December contains the following examples:
- An Offer You Can't Refuse: The Towada family gives the initial impression that they influence people this way with townspeople being afraid that their entire livelihoods would be threatened if they crossed the family.
- Brick Joke: Why Masaki volunteers to clean the garage.
- Foreshadowing: Shiro's casual statement that she has mothered children along with the idea that she could turn Masaki into a god.
- Furo Scene: Starts with Masaki alone. Yuki tries to join in. It ends with everyone in the main group joining in the end, though Masaki is the only one actually naked.
- Fridge Horror: In-Universe example. After Yuki's father is happy that Masaki did not become another "victim," Masaki realizes that Yuki's parents are 34 while she's only 17 and does the math from there.
- Gosh Dang It to Heck!: Mizuho's Angrish-filled rant that ends with her calling Shiro a, "Fidiot-ass-munching-pud-whacker!"
- Indy Ploy: How Masaki manages to win against Yuki in a sparring duel.
- Noodle Incident: The entire situation of putting Kouhei on a crabbing ship that gets attacked by pirates and he somehow still makes it back in time for the New Years party.
- Secret Test of Character: Why Mashiro has Masaki spar with Yuki. She wanted to see how he fought instead of seeing if he'd win.
- School Swimsuit: Mizuho is briefly seen wearing one when she arrives during the Furo Scene.
- Shotgun Wedding: The fate of the men seduced by the Towada women for the past 100 years. Yuki's father is very happy that Masaki didn't fall into the same trap he did.
- Take a Third Option: The first chapter's resolution: Freeze to death while stranded in a shrine vs. utterly humiliating the daughter of the most powerful family in town? Masaki would rather run the risk of climbing down the mountain in the middle of a blizzard with Yuki on his back!
- Take Our Word for It: The narration's description of "the amazingly beautiful and intelligent doctor with great legs," who insists on being called such near the end.
- Thanks for the Mammary: Masaki accidentally ends up with his hand on Yuki's breast after taking a tumble with her.
- Wham Line: Yuki loudly announcing to Masaki that she's ready to "make a Yayako" (have a baby) with him after only knowing him for two months.