There are many iconic trios in the anime world, some composed entirely of villains, others of heroes, or a mix of the two. In a trio, however, there are ongoing tensions, a strong sense of competition, and rivalry that can also become jealousy which makes the whole group that much more interesting. RELATED: 10 Best Anime Duos Of All Time, Ranked There is always a sense of co-dependency, a need for the two characters to continue on together and it makes their relationship stronger. In a duo, characters either complete one another or challenge each other.

The relationship dynamics in a trio are more complex and delicate than in a duo which makes them, according to the 'Rule of Three', more humorous and effective.