Looking for the title of an old hentai/anime series

Hello all,

I am trying to find an old hentai that I really liked and I'm hoping people can help me out. The general premise of the story was that the protagonist moves back to his rural hometown where he proceeds to meet two childhood friends who are sisters. He has sex with both of them but the feelings between them don't really solidify. The younger sister he has sex with in a classroom and the elder a swimming pool - odd thing I remember, in the classroom scene it has a panel of two hercules beetles having sex that the couple mentions in passing as justification for the sex. The story proceed into a harem where the main character becomes romantically involved with multiple girls throughout the story (I think it ends up being 5-7) and then the final chapter/episode has all of the girls and the protagonist getting together at a summer fireworks festival at a shrine. If anyone has any leads they would be much appreciated as I've had no luck searching so far - the story should be from the early 2000's to 2010 in terms of publication date (huge range I know but thats the best I can remember).

Thanks all,
ThatGuySteve.

P.S. If this doesn't follow forum rules for some reason please let me know mods and I will edit it accordingly!

I really just should have asked here earlier! That was indeed the series, thank you very much! In regards to my mistake in the final scene I think its been 8-9 years since I last read it so me making a mistake doesn't surprise me.