Otsuki Mitsuoki was the son of Mitsuyoshi, the third-generation master of the Otsuki school, a lineage the published sources repeatedly call "a distinguished lineage among the Kyoto metalworkers." He was born in Kyoto in Meiwa 3 (1766) and died in Tenpo 5 (1834) at the age of sixty-nine. He studied painting under Kishi Ganku and is said to have maintained close ties with Nagasawa Rosetsu, associations that decisively shaped what the examiners describe as an artistic manner that is, "in the truest sense, painterly." He employed a profusion of art names, Ryusai, Dairyusai, Ryukomado and Shiryudo among them, and signed in varied forms including "Yoshu Mitsuoki," "Gekko Mitsuoki," "Tsuki Mitsuoki," and "Mitsuoki" written with variant characters. The published sources record that he used a tripod-shaped seal (kanae-in) as a seal-mark, yet among the pieces here it appears on only three; most are signed with the name alone or with a , as on the of a hawk on a pine.
Mitsuoki's technical range encompassed (high-relief carving with polychrome metalwork), (single-chisel engraving), (flat inlay), and (relief modelling from the plate), all of which the describes as "executed with great skill." He worked across an unusually varied palette of metals, iron, , , and brass, with the last appearing "especially often" in his oeuvre. His plates were finished variously as (polished), (fish-roe stipple), (rough), and - (file-mark), each selected to serve the pictorial demands of the subject.
On he deliberately varied both outline forms and materials across his production, favouring such subjects as geese amid reeds beneath the moon, snow resting upon reeds, and literary narratives drawn from Chinese and Japanese tradition. The observes that by "adjusting the degree of modeling" he was able to "skillfully convey the tonal gradations of brushwork, as well as mist and the rippling of the water's surface," and that in his works the carving is "remarkably refined, with exceptionally assured and finely textured surfaces." His compositional intelligence is noted for its command of open space, its narrative pull, and its ability to communicate atmospheric depth. On the Sagicho festival , and fine line engraving are used throughout, inlay is used in abundance, and the figures are rendered "with such verisimilitude that they seem about to step into motion."
The published sources date part of his work by the hand of the signature. Two pieces are judged early works from their clerical-script (reisho) style of signature: a of an old tree with a bird of prey set boldly to left and right of a gently rounded square brass plate, and a . A third, a brass of a lone old cedar under a half-moon in mist, they call his early work outright. The early pieces already show his force. On that , an immortal riding a sedge hat over raging waves is carved in a "forceful rich in technique" over the , rendered with "compelling realism" as if about to spring from the surface. At the other pole stand the brass guards worked in , where the gradation of the relief carries the brushwork, the mist and the moving water.
The published sources read in his modelling the influence of the great Kyoto predecessor Myoju and, in his pictorial composition, the influence of Kaneie. Their judgments of his work return to a few phrases: that a piece is one in which one can "fully sense Mitsuoki's abilities," and that his manner is "pictorial in spirit." They consistently place the Otsuki school among the distinguished Kyoto lineages and call Mitsuoki a pillar of it, a painter-trained carver whose works carry "strong narrative pull" and lyric depth. That is his standing among the chokinshi of the late period.
For the collector, Mitsuoki's designated record is thirteen works, all at the rank: eleven and two . There are no pieces among them, and no current holder or old provenance is recorded against them. One is kept in a box of the Ryushido with an ink inscription by the Meiji master Unno Shomin. His work comes to light from time to time rather than often, and a signed in brass, the metal the published sources name as his most frequent, with a landscape or a reed-and-goose subject composed like a painting, shows the side of his art they praise most.