Shinkaku 心覺 (1117–1180), Shingon-line Siddham scholar of the Ninna-ji 仁和寺 lineage in mid-Heian Kyoto, son of the Fujiwara aristocrat Fujiwara no Akiyori 藤原顯頼. He trained at the Ninna-ji under Kanken 寛遍 and became a senior Shingon teacher in the Hirosawa-ryū 広沢流 esoteric lineage. His chief surviving work is the Tara-yō-ki / Shittan yō-ki KR6t0418, a three-fascicle Siddham scholarly treatise notable for its pedagogical use of the iroha-Siddham correspondence as a Japanese mnemonic for the fifty Siddham letters. The DILA authority id is A001254. He died at Ninna-ji in Jishō 4 / 1180, age 64.