蝦夷方言藻汐草

Turesi is a documented sister form and gives a direct reading to the final シ of ツ゚レシ. Tures remains possible because historical kana can supply a vowel after final s; the source alone does not establish the morphological choice. The marked ツ゚ supports tu. Dictionaries distinguish the usual brother-to-younger-sister relation and literary extensions to a lover or wife, with some exceptions. Narrative examples must therefore be interpreted in context rather than all counted as literal younger sisters.