盟 is a Japanese kanji written with 13 strokes, listed here under the keyword “alliance”. It is built from 明 (bright) and 皿 (dish). In Remembering the Kanji by James W. Heisig it is frame 1558.
On KumiJi Glyph Explorer, open the parts search and type “bright” + “dish”. 盟 is among the results, together with every other character containing the same shapes.
Open 盟 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.