The Kirat Rai script is an abugida used for writing Bantawa, an eastern Kiranti language of the Sino-Tibetan family. Bantawa is spoken in Sikkim and Nepal by almost 400,000 people. The script appears to be a modification of Khambu Rai, which is used for writing the same language.
Kirat Rai is written with thirty-one consonant letters each containing an inherent /a/ vowel, seven vowel diacritics for changing the inherent vowel, a virama for cancelling the inherent vowel, and a vowel carrier which can be used in combination with the vowel diacritics for writing word-initial vowels.
This script is not currently recognized by the ISO 15924 standard, but is included in ScriptSource for research purposes. If you have any information on this script, please add the information to this site. Your contributions can be a great help in refining and expanding the ISO 15924 standard. The Script Encoding Initiative is working to support the inclusion of this script in the standard, and contributions here will support their efforts.