Takahashi Yoshitsugu (高橋良次, read Ryōji in some translations of the published sources) was born in Tenpō 13 (1842) into the family of the metalworker Tōunsai. He first learned metal carving from his father and from Shibahara Toshiyoshi, and then became a pupil of Tōryūsai Kiyotoshi, the Bakumatsu master of the Tanaka line. The published sources call him one of the skilled hands among Kiyotoshi's pupils, and they name Okada Sekiga as his own pupil. He died young, in Meiji 6 (1873), at the age of thirty-two.
He is known in the designated record through four complete mountings, each fitted with a unified set of his metalwork ( ). On a late- every fitting, from the , long , and to the and the , is of solid gold (-muku), worked in with gold, silver and applied devices, flat inlay, and . On a tsukubei mounting of the kind fashionable at the end of the period, his solid-gold fittings are carved in with chrysanthemum sprays, while the is by Matsuzaki Naritoshi and the lacquer by Rikuyūsai.
His subjects are auspicious and literati themes carried through a whole mounting. On the , scattered fans carry the hermit-poet Lin Hejing, a tortoise, young pine, adonis, orchid, peony, plum, bamboo and chrysanthemum. With the black lacquer scabbard they make up the Three Friends of Winter, the Four Friends and the Four Gentlemen. The published sources write that there the splendour of gold and the elegance of the design are fused to fine effect. The tsukubei mounting is likewise designed as the Four Gentlemen, and they call it a particularly accomplished example, thoroughly in the taste.
A shows a quieter register. Its scabbards are of ironwood (tettōgi), the long sword mounted with a and the short sword as an , and his fittings carry a single theme of autumn grasses throughout. The daitō are polished solid gold in high relief, the is polished with flat gold and silver inlay, and the shōtō fittings are silver with gold and colour. The published sources call it a refined in which the autumn-grass fittings stand out vividly against the subdued ironwood.
His last recorded work is an inscribed on the with a winter day of the year Kōgo (1870). All of its fittings are solid gold carved with chrysanthemum blossoms, the and in high relief and the split-signed 良 and 次. The published sources call it a powerful work by an artist who died at thirty-two.
All four of his designated works are in the tier, three of them late- mountings and one of the early Meiji years. His short working life makes his output small, and a complete mounting by him in solid gold is a rare thing for a collector of Bakumatsu metalwork to encounter.