This character is a Other Symbol and is commonly used, that is, in no specific script. The character is also known as tanabata tree with wishing papers.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+1F38B offers a line break opportunity at its position, except in some numeric contexts.
The CLDR project calls this character “tanabata tree” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: banner, celebration, Japanese, tanabata, tree.
This character is designated as an emoji. It will be rendered as colorful emoji on conforming platforms. To reduce it to a monochrome character, you can combine it with Variation Selector-15: 🎋︎ See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
Tanabata (Japanese: たなばた or 七夕, meaning "Evening of the Seventh"), also known as the Star Festival (星祭り, Hoshimatsuri), is a Japanese festivals originating from the Chinese Qixi Festival. It celebrates the meeting of the deities Orihime and Hikoboshi (represented by the stars Vega and Altair respectively). According to legend, the Milky Way separates these lovers, and they are allowed to meet only once a year on the seventh day of the seventh lunar month of the lunisolar calendar. The date of Tanabata varies by region of the country, but the first festivities begin on 7 July of the Gregorian calendar. The celebration is held at various days between July and August.