During their school days, they relied on each other since they were both isolated. In some way, a relationship by pure chance.
They both have a similar background, a family environment lacking the stability for them to grow up healthily. However, they came out in opposite ways. She is energetic and often acts carefree, while Togi was dejected and unmotivated. What they both had in common was their inability, or more of unwillingness, to form bonds with anyone other than each other, as well as their love for different subcultures.
To be able to hang out outside of school, she proposed the idea for him to pretend to be a girl so she could report to her family. It wasn't difficult for him, for his build was small and his face was androgynous. The way his face resembled his mother disturbed him at first, but it faded as they explored different makeup styles.
He realised he was really good at it, becoming someone else away from the uncontrollable cage associated with Otose Togi. His greatest enjoyment during his high school days was hiding in his own corner, thinking in his own head mockingly (or more so in a chuunibyou manner), that if they don't know his secret side.
Their relationship didn't last very long. To his surprise, she had managed to befriend people in their class on the school trip he couldn't go to. The string of security he held onto was gone the moment she ventured out of their bubble. Even though there was a period of awkwardness, they remained friends afterwards.
Something that could be said about Togi's "type" are people who are analytical and can read him well.