Took me 3 hours of retries to finally get the ending with the H-scenes. And it was worth it. The VN is amazing. Really enjoyed it. I hope there will be more to come with other characters or even Dawn 2.0 in the future :D
You need to get the 1st scene right and win the contest in order to trigger the H-scenes in the post-contest. Not sure what I clicked exactly but I tried to spend as much time as I could with her by grooming, talking to her once about her adventures (including breakfast to maximise the day) and the contest + battles. Scyther MUST learn the new battle move + contest appeal move too.