慨 is a Japanese kanji written with 13 strokes, listed here under the keyword “rue”. It is built from 既 (previously) and 忄 (heart). In Remembering the Kanji by James W. Heisig it is frame 1595.
On KumiJi Glyph Explorer, open the parts search and type “previously” + “heart”. 慨 is among the results, together with every other character containing the same shapes.
Open 慨 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.