I used Windows 10 before, and now switched to Ubuntu MATE 16.04. I got the Japanese input working quite nicely with Mozc. However, in Windows you could put in the Romaji and they would transit into Kana immediately, whereas in my case there is basically a keybinding for each symbol. I could get used to it, but it's not that convenient after all.
I would appreciate your help.
P.S. Sorry for the noobish style, I started using Ubuntu like a week ago.
21 Answer
It can be toggled in Mozc Tool -> Configuration Tool -> Input Method. Set the method to Romaji and the latin characters will automatically transform into Kana, and ultimately, Kanji. Case closed.