heart sutra
Gyatei gyatei haragyatei harasoogyatei boji sohaka
Gone, gone, gone to the other shore; Gone completely to the other shore. Svaha.
The Heart Sutra is a Mahayana Buddhist sutra referenced, among other things, with the phrases "gyate" and "zemutodoshu" in Kasodani Kyouko's sprite in Touhou's Ten Desires; these two phrases are, therefore, often spoken by or used to refer to Kasodani Kyouko in fan art.
The tag can be used for any clear reference to the Heart Sutra, though the catchphrase "gyate" is probably the most common usage.