This project as such is not exactly fictional. There was a real Japanese Navy 'C4' competition in 1938 that spawned an Aichi C4A proposal (model AM-20), and a wooden mock-up was even built before the design was cancelled in favor of the Mitsubishi C5M (a naval variant of the Army's Ki-15 "Babs").
As that aircraft has never been portrayed before, I attempted to imagine it by modifying an AM-19 "Jake" (E13A1) color profile and fitting various elements from an AM-17 "Val" (D3A2) such as the cockpit and landing gear (see original color profile below right).
Of course this is purely speculative and should not be taken seriously as it is only my vision of the aircraft and not based on actual facts.