Nick Steeves pointed out to me that tc.el in emacs-goodies-el is trivial-cite. So no urgency to package this. Feel free to just close it if you think there are better options already for Emacs.
- Bug#904861: RFP: elpa-tc -- Japanese input method with T-cod... David Bremner
- Bug#904861: Acknowledgement (RFP: elpa-tc -- Japanese i... David Bremner