The “animation” aspect refers to the 2015-2016 OVA (Original Video Animation) production by studios like Pink Pineapple or Mary Jane—though specific studio credits vary. Two or three episodes were produced, each roughly 25-30 minutes long.
For non-Japanese speakers, a verified version usually implies professional-grade subtitles that capture the subtle linguistic nuances of the "elder sister" honorifics and emotional dialogue. Legacy and Influence aneki my sweet elder sister the animation verified