I was thinking the same as Paperdragon. Dojos get to be 9-10 inches, and need lots of space, because they swim a lot. Mine remind me of seals. They either lounge in my floating plants or they are all over the tank doing incredible acrobatics. Mine seldom hide and are usually all over the tank.
Use your 10 as a quarantine tank, and get a 55 for the Dojos. They grow quickly. Mine were your size when I got them, and in 6 months they were 6" and as big as my thumb. Feed them well. Mine like to suck worms from my fingers. A little off putting the first time they did it. I wasn't expecting it, but now I love it. Their whiskers grabbing my fingers as they suck the worms from my fingers.

Find some food they like and they will come out more. (Of course, take care, not to overfeed)
When you set up your 55 (you have a little bit of time), use Pool filter sand for the substrate, and you will have happy Dojos. There are other cool-loving peaceful fish you can add in with your Dojos when you get a bigger tank. Also Dojos like the company of Dojos, so when you get a bigger tank, get some more Dojos. They will be braver and happier. Mine lay in a pile together. Keep in mind that bigger tanks are more stable in temperature and in chemistry. They are much easier to keep. I am a relative beginner and started out with small tanks, making the mistake of tanks too small for my fish, so now I have 10 tanks (most of which are small), a couple bigger ones and two are quarantine tanks.
Good luck! Tanja.