History so far:

:The Beginning:
During his return to Japan from institute, he rode a bus which supposed to lead him back to Tokyo. However, as he walked down from bus, he's not already in Tokyo. Instead, he entered a dimensional disorder world, and the place called the Dressing Room (DR). At first, he's completely lost on what was going on. After few days of confusion, he learned himself he couldn't return to his world, he set a new home in DR.

Kaito lived alone as a free man, without job, no more strict schedule, like his own holiday. Not just him arrived the place, his Vocaloid family members; cnstructionzone and 13376066135 eventually appeared in DR. Which brings him to joy and not being alone.

:Non-blood Ties:
One day, three of them were taken back to their world, the institute having a festival. Kaito met justanimitator which he met once in DR. Knowing he's alone and shares the same history as Kaito, he made a decision. He decided to adopt Len as his younger brother with a promise, even though Len is a robot. It took only a day to spend with Len in real world, then he was separated.

Few days later, Kaito awakes in DR and wandering around the street. There he saw Len, where he met in the festival. He and Len reunited as 'unofficial' brothers and spend most of time together.

:The Development:
When go_google_it appeared in DR, Len always wonder if he has a 'real' family member. Kaito recalled Len is a VOCALOID2 application, which came in two voices; Kagamine Rin and Len. Kaito made research about this and learned himself how to fix robots. Two weeks after his trainings, he finally able to scan system inside Len, and he found out imitationsecho is 'sleeping' inside him.

There's a chance to wake her up and living in reality, unless if he has another empty shell of a robot with a 'heart', Rin is able to revive. Kaito find himself an abandoned laboratory, and starts working with creating a robot. To be judge by Rin's development, she will be done by December 27th, Kagamine's birthday, as well as Christmas.