Breakdown of tomodachi to hamorou.

Questions & Answers about tomodachi to hamorou.
ハモろう is the volitional form of ハモる.
- ハモる = to sing/play in harmony, to harmonize
- ハモろう = let’s harmonize / shall we harmonize
So the ending -ろう here gives the sentence an inviting, suggestive feeling.
The dictionary form is ハモる.
This is a casual verb, and its volitional form changes like this:
- ハモる → ハモろう
This follows the pattern of many う-verbs:
- 歌う → 歌おう
- 帰る → 帰ろう
- ハモる → ハモろう