was a Japanese daimyà  of the Edo period, who ruled the Koga Domain. He served as a rà Âjà « for Tokugawa Ienari during the Tokugawa shogunate.
Toshitsura was born in 1789. He was known to have a scholarly inclination and surrounded himself with individuals who were scholars, artists, and calligraphers.
One of ToshitsuraâÂÂs greater cultural legacies are the diagrams he made of 86 types of snowflakes that he catalogued in a book he titled the Sekka zusetsu, published in 1832. He made his drawings by observing snowflakes with a Dutch microscope, and his drawings became popular among the artists of the time, who petitioned to see his work. He would later expand his categories to 97 in 1840. Toshitsura decision to bring his vassal Takami Senseki, a prominent retainer of the Koga Domain, to Nagaskiin 1836 resulted in the reproduction of a 'world map' which modern scholars have celebrated for relating trade routes and art of the time.
In 1837 Toshitsura stopped a revolt led by Oshio Heihachirà Â, defending the castle of Osaka from Oshio's rebellion.
Among the officials of the Bakufu, Toshitsura was one of the daimyà  who were affected by the October 7, 1843 tempà  reforms. Toshitsura, who was then a rà Âjà « and held fiefs in Shimosa and Settsu, was in a position to have 13,000 koku of his Settsu holdings to be confiscated by the Bakufu. Despite his previous support for Tadakuni's reforms, this threatened to render him financially insolvent due to debts owed to his peasants. When he failed to negotiate a settlement with his peasants he instead attempted to oppose the Shogun's requests, a decision that rivals tried to pressure him with. Toshitsura would succeed though in getting the Shogun to halt his fief reformation plans.
Toshitsura was succeeded by Abe Masahiro in his capacity as rà Âjà « in 1845. He died in 1848.