[NecocYaotl]

Keima told Kanon that he can't monopolize Kanon. While she thought of it as he dumping her, I think she follows Keima's last words so she can shine by herself. Her song is not dedicated for one person and only, but towards all of her fans. If not, Keima capture would mean nothing to her.
No need to tell me to read the omake, I read them already.
EDIT:
It will be better not to take omake as reference, because we just found out from the latest chapter that the memory won't stay intact even if the girl possess a goddess, she still forget about it and remember it only after some period of time and the love get strong enough to make the goddess awaken.
The omake kinda similar anyway, they show different reaction to Keima or something that related to the memory with him and they don't remember why :
- Ayumi stopped calling Keima otamega
- Mio wanted to whip Keima
- Kanon reaction to kiss and katsura
- Shiori writing a book
- Kusunoki reaction to ice cream
- Chihiro heartbeat when she thought of who will become drummer (incidentally fits up Keima)
- Nagase thought of Nikaidou's too-revealing-outfit inappropriate as teacher make her vaguely remember that she herself kiss a student
- Tsukiyo gazing at Keima (although the 4-koma heavily focused on Luna so no confirmation whether Tsukiyo remember or not)
- Minami wanted to marry someone who also has spring-up hair
- Sumire vaguely remember she had a special someone
- In a shogi game with Tenri, Nanaka thought she lost the game when Tenri took her "Keima"
- When Yui saw Keima, she thought it won't be a problem if she wear male's suit in her wedding because the male can wear wedding dress instead
I don't count Rieko as candidate, but in the omake, her memory isn't erased and she still remember Keima. Although it will be funny to have a grandma as someone who possess a goddess.