Pianonymous: One of my sources for information about the early history of Hohner Melodicas has been 1960s-70s editions of the English language magazine, The Music Educators Journal, published for elementary and secondary music teachers. This is probably comparable to the Japanese magazine to which you have referred. The Music Educators Journal did not make many references to the melodica in its articles, but it did include advertisements and announcements from Hohner. These are helpful in dating early Hohner models. I have examined all issues of this journal and have copies of advertisements and announcements.
If I have understood you correctly, your information about the advertisement of the PC-1 Tokai Pianica in 1961 is very important for my research, which otherwise shows that the first (piano style) Japanese Keyboard Harmonicas appeared in 1961 and were made by Suzuki (The Super 34 Melodion) and Tokai Gakki. The first Yamaha Pianicas were created and manufactured by Tokai and were sold both under the Yamaha name and under the Tokai name. But the PC-1 seems to have been sold only under the Tokai name and to look more like a Clavietta. The Super 34 also looks to me more like a Clavietta than later Suzuki models. You probably know more about all of this than I do. I wrote a letter to Tokai Gakki asking about their relationship with Yamaha. They told me that the Pianica was created and manufactured by Tokai for Yamaha, but that eventually Yamaha made other arrangements for the manufacture of its Pianicas. I think it was sometime later that Yamaha moved the manufacturing to Indonesia.
I think Tokai Gakki still makes some of its own Pianicas, but I have not seen one. They seem to mainly make guitars. There are some other brands that identify their keyboard harmonicas as Pianicas. I wonder if Tokai still owns the rights for “Pianica” and has an agreement with other companies to use that name. Kioritsu sells Pianicas. I have one and it is inferior to Yamaha. Here is a link for current Tokai models:
I have not ordered one, because they look as though they are more cheaply constructed.