Asaden, also known as the Asakusa Electronic Music Instrument Workshop, is a Japanese boutique maker based in Tokyo specializing in analog electronic instruments. The workshop is best known for the Ondomo, a compact modern interpretation of Maurice Martenot's ondes Martenot. Designed by Naoyuki Omo, who builds the electronic and mechanical components, with wooden cases constructed and painted by Yasuko Omo, the Ondomo distills decades of research into the ondes Martenot into a portable instrument roughly 64 cm wide and 6 kg in weight.

The Ondomo preserves the traditional playing techniques of its ancestor: a four-octave keyboard with lateral movement for vibrato, and a finger ring connected by thread for continuous glissando control. A small tiroir (drawer-style controller) selects between analog oscillator waveforms and mixes the output between a built-in speaker and external amplification. Asaden produced a limited run of 100 hand-assembled units, and the instrument has drawn attention from experimental and film-score musicians interested in the ondes Martenot's distinctive vocal, wavering tone.

Asaden has 1 product cataloged on Equipboard, including Synthesizers.