U+104C6 Osage Capital Letter Sa

The Wikipedia has the following information about this codepoint:

The Osage script is a new script promulgated in 2006 and revised 2012–2014 for the Osage language. Because Latin orthographies were subject to interference from English conventions among Osage students who were more familiar with English than with Osage, in 2006 the director of the Osage Language Program, Herman Mongrain Lookout, decided to create a distinct script by modifying or fusing Latin letters. This Osage script has been in regular use on the Osage Nation ever since.

In 2012, while in the process of submitting the script to Unicode, a more precise representation of the sounds of Osage was formulated, and by the following year had been adequately tested. In February 2014, a conference on standardizing the reforms was held by Lookout and the staff at the Osage Nation Language Department along with UCS expert Michael Everson. The result included the introduction of case, the abolition of two letters, and the creation of several more.

The Osage script was included in Unicode version 9.0 in June 2016 in the Osage block.