A third common theme could be sacrifice. In some fanfics, Len's possessiveness might lead him to sacrifice his own desires or opportunities for Rin's sake. He is so focused on her that he is willing to give up things to ensure her well - being and to keep her close to him.
One popular 'possessive len x rin fanfic' could be 'Len's Unwavering Devotion to Rin'. In this fic, Len shows his possessive side as he protects Rin from various challenges. It delves into their relationship in a really interesting way, with Len being extremely protective and his actions being driven by his deep love for Rin.
A fanfic that stands out is 'The Three - Voiced Ensemble'. This one delves deep into the relationships between Rin, Len, and Miku. It explores not only their musical collaborations but also their personal growth. The author does a great job of showing how they support each other, like when Miku gives advice to Rin on how to improve her high - notes, and Len encourages them both during a tough musical competition. It's a long and engaging fanfic that really captures the essence of these three characters.
There's a fanfic called 'Len and Rin's Harmonious Journey'. In this fic, they embark on a journey to discover new musical notes and in the process, their bond deepens. It's filled with sweet moments and some really nice descriptions of their interactions. For example, there are scenes where they collaborate on creating a new song, which shows their synergy very well.
One common theme is their relationship, exploring the different dynamics between them, whether it's a cute and innocent friendship or a more complex romantic connection.
In a good Rin x Len x Miku fanfic, the setting can play an important role. It could be set in a modern music studio, a virtual world, or even a magical realm. The setting should enhance the story and the relationship between the characters. The story should also have a clear conflict, whether it's an external force trying to break up their musical group or internal differences in their creative ideas. Resolving this conflict in a satisfying way is what makes a fanfic really good.
Fanfiction.net is another place to look for len x rin fanfic. There are many writers who post their works there. However, the quality may vary, so you might need to do a bit of sifting through. But it's still a great resource as there are some hidden gems among the numerous stories available.
Friendship is also quite prevalent. Their unique connection as Vocaloids can be seen as a strong friendship in many stories. They support each other, have fun together, and grow together through their experiences.
You can try some popular fanfiction websites like Archive of Our Own (AO3). There are often a large number of well - written rin x len fanfics there. Just search for 'rin x len' in the search bar and you'll get a list of relevant works.
One popular Vocaloid Rin x Len fanfic is 'The Melody of Their Hearts'. It beautifully depicts their relationship through a series of adventures in a magical music - filled world. The story has a great balance of cute interactions and deeper emotional moments.