Designed as an electronic message board for the home ("Dengon" translates as "Message"). The proprietary tape cartridge holds up to 60 seconds of audio. The tape is the standard 0.15 in. width used in cassettes (often approximated as ⅛ in.). The instructions mention that additional cassettes will be sold separately. This one does not have graphics printed on it—Mr. Dengon, Made in Japan—like other examples on the web (Taylor 2018).

Mr. Degon comes with four plastic cards that are inserted by the user to start recording or playback, depending on which end is inserted into the slot representing Mr. Dengon's smile. All four cards are identical. They can be written on with a felt-tip pen to identify family members. A message is recorded by speaking into the hat. The appropriate card is then left in the grip of Mr. Dengon's hand to indicate that a message waits for the person named on the card. The other hand can hold a pencil, presumably to allow the receiver to write the message down on paper (which the originator could have done in the first place, of course, thus eliminating the need for the recorder at all.)

There is at least one other member of the Dengon series: the Dengon Clock, which uses the same cartridge to record audio and play it back when the alarm goes off (Mattock 2022;  WorthPoint 2025b).