Jounetsu Tairiku (Passion continent) is a long-running documentary series with over 1200 episodes showcasing the daily lives, struggles and triumphs of various people⁰. Now Kajii has made her own version: Jounetsu Kajishima Tairiku, showcasing her struggles and triumphs during the shooting of the Custom Nikichan music video. Not really, it's just a cute behind-the-scenes making-of compilation. The little snot-flute ditty she plays at the beginning is a version of the theme song to Jounetsu Tairiku, coincidentally also named Jounetsu Tairiku.
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Here for example is a Jounetsu Tairiku episode featuring my beloved Mizuhara Kiko from years back.