Append is a serious, collected and brave fifteen year old boy who is also the unofficial vice leader of the Len modules. Append is a strong individual who always asserts his position in a matter and fights for what he stands for. His best friend is Kagamine Len who he will rush to the defense and aid of at any given time. Append also enjoys spending time with Blue Moon as they share similar views regarding people. However, the blonde boy's bold nature has caused him to make several enemies in the Len household including Trickster, Gigantic OTN, Plus Boy and Punkish. Despite this, no Len module can deny that he makes an excellent leader and serves as a good role model for the household.