Introduction The phrase blends colloquial Japanese with slang and a playful ending ("new" ≈ dialectal or internetified "ne/yo"), packing contrasts: physical largeness ("dekai") versus emotional or social absence ("mi ni kona(i)"). This tension—visible presence versus actual availability—invites exploration across four themes: physicality and identity, sibling relationships, absence and longing, and register/dialect as social signaling.

The final question embedded in the keyword is an invitation without a destination. You cannot literally “go see” this otouto because there is no consistent referent. And that is exactly the point.

• "Dekai" (huge) foregrounds physical scale. In modern media, a sibling’s outsized body can function symbolically: protector, source of intimidation, or object of envy.
• Large physicality confers expectations (caregiving, athleticism, emotional stoicism). Narrative friction arises when those expectations clash with the person’s behavior or choices.

• It’s a typo from smartphone swipe input.
• It’s a blend of mi ni koi (come see – imperative) + nai (negative) = contradictory nonsense.
• It’s simply more funny when incorrect.