Ok, I also searched the word processor ROM (EC702) for any mention of either Konami, Canon or anybody else and could not find anything. I also tried running it, but could not easily figure out how it worked. Something with the STOP key I understood (from the screenshot on GenMSX), but nothing seemed to do anything.
There is one other Canon program listed on GenMSX that seems like it was a word processor, V-Word. Listed publication date is 1986 (a year after the Konami edition), but the price is identical. Also 34800 Yen. Unfortunately no screenshots or pictures. http://www.generation-msx.nl/software/canon/v-word/release/839/
EC-702 should be purely Kanji-ROM and according to another MSX user (and ROM examiner) it's usable also with other software which looks for Kanji-ROM from the computer.
Ohh I know EC-702 can be used by other SW looking for a Kanji ROM. I would not be surprised if the Kanji ROM was actually made by some party like ASCII and then licensed and sold by others with perhaps some small customizations. It seems highly unlikely that everyone wrote their own: https://www.msx.org/wiki/Kanji-ROM
On page 172 there is a news item, and you will see a set of cartridges that look, apart from the Canon label, identical to the Konami word processor cartridges. The price is also identical, and the screenshots are a match from those from the Konami cartridges.
So I have updated the wiki to reflect that these cartridges were indeed from Canon, and not made by Konami.
Note: In the text they say that the product code is VWU-100, but that is a typo as on the cartridges you can see it is actually VW-100.
