KanjiJLPT N1
ThatRadical: Squid

Mnemonic

A sweet aroma rises from one ancient flower. A bird spreads its wings and dives straight toward it. You point and declare: 'That! That is the exact flower I told you about!' The bird knew precisely which one you meant.
Additional thoughts
Picture yourself pointing decisively at a single sweet-smelling flower while a bird with outstretched wings confirms your target. The pointing gesture anchors the demonstrative sense of the kanji.
Quick recall
A sweet scent from one flower draws wings — you point: 'That one!'

Details

The keyword for 其 is that. This kanji is a demonstrative character used to refer to something specific, functioning as a pronoun meaning "that" or "its." In classical Chinese and Japanese texts, it serves as an important grammatical word pointing to a previously mentioned or contextually understood object or concept. It carries a sense of definite reference, directing attention to something already established in discourse.
On'yomi
き、ぎ、ご
Kun'yomi
それ、その