This manga has a sort-of rough start. If you are coming from the anime you will surely be pleasantly surprised at how the manga differs and grows throughout the story. The story in the manga begins to branch off from the premise of renting a girlfriend all while never forgetting it.

The development of characters such as Chizuru becomes one of the best things about this manga and as the story progresses I found myself forgetting it was even Rent-a-Girlfriend. If you even slightly found the anime enjoyable and are curious about where the story goes after, I highly suggest you read the manga.

Even characters you don't like are not as bad in the manga (looking at you Ruka). Near the beginning of the series, the characters are not the greatest and you may even dislike Kazuya and find him cringy. Don't worry I did too. The greatest thing about having a meh character is how much room for growth there is and the path that Kazuya takes to become a man he can respect is worth reading in and of itself.

If you enjoyed the anime or are just wondering if the manga is good at all, imo its 10x better than the anime and then some. I found the anime unwatchable at times due to the highly cringy moments Kazuya would bring about but the manga is in a different league of quality.