There is an episode that Soshitsu took "Senjimon" (the Thousand Character Classic), Kobo-Daishi Kukai's autograph, from Honno-ji Temple in the Honnoji Incident.
逸話として、本能寺の変の際に宗室は弘法大師空海直筆の『千字文』を持ち出したと言われている。