One great source could be Archive of Our Own (AO3). There are many talented writers on there who create interesting stories about Ren x Aoba. Just search for 'dmmd Ren x Aoba' in the search bar and you'll find a variety of fanfictions with different themes like adventure, romance, or mystery.
Romance is a very common theme. Writers often explore the deepening relationship between Ren and Aoba, from their initial attraction to a more profound emotional connection. Another common theme is adventure, where they go on quests or face challenges together in the DMMD world.
You could also try Tumblr. There are many fanfic writers who post snippets or links to their 'aoba x ren fanfiction' on their blogs. Sometimes, Tumblr users also form communities where they discuss and recommend different fanfics. It's a great way to discover new and interesting stories about this pairing.
There's also 'Aoba's Encounter with Ren'. This fanfic focuses on a specific event that brings Aoba and Ren closer. It's really interesting as it shows their different personalities interacting in a new situation. The author does a great job of capturing their essence.
I'm not sure specifically which 'aoba x ren lemon fanfiction' stories are good. You could try searching on fanfiction - dedicated websites like Archive of Our Own. There might be a variety of works there, but make sure to follow the website's rules and regulations.
One great fanfiction could be 'The Journey of Koujaku and Aoba' which focuses on their adventures together in the DMMD world. It delves deep into their relationship, showing how they support each other through tough times.
Social media platforms can also be useful. For example, on Tumblr, there are many fandom - related blogs that might post or reblog Ren x Aoba fanfiction. You can use the search function on Tumblr to look for relevant posts, but be aware that the search results can be a bit chaotic and you might need to dig a bit to find exactly what you're looking for.
One common theme is probably their relationship development. It could be about how they first met and how their feelings grew over time. Another theme might be adventure, with them going on some sort of journey together.
One great koujaku x aoba fanfiction is 'Aoba's Discovery'. It delves into their relationship in a very sweet way, showing how they support each other through various challenges. Another one is 'Koujaku and Aoba: Unspoken Bonds' which focuses on the unspoken feelings between them and how they gradually come to the surface.
There's a fanfiction called 'Mink and Aoba's Adventure'. In this story, they embark on a journey together, facing various challenges that test their friendship and loyalty. It's full of action and heart - warming moments. The author does a great job of capturing the essence of the characters and their dynamic.
Love and attraction are also common themes. Many fanfictions depict the growing romantic feelings between Koujaku and Aoba. It can be a slow - burn kind of love or a more immediate attraction. Additionally, the theme of self - discovery is present. As they interact, they both learn more about themselves.