1.
mood, spirits, energy level
One's level of excitement, enthusiasm, or emotional energy. High tension means being upbeat and energetic; low tension means being down or unmotivated. This is a wasei-eigo usage distinct from the English meaning.
2.
tension (English meaning)
Physical tension, tightness, or stress (the original English meaning). Less common in everyday Japanese than sense 1.
Etymology: From English "tension," but used with a different meaning in Japanese (和製英語). In Japanese, it primarily refers to one's mood or energy level, not stress or tightness.
Caution for learners: In English, "high tension" suggests stress or anxiety, but in Japanese ハイテンション means "excited" or "energetic." This is a common source of misunderstanding.
Common expressions
- テンションが上がる (to get excited, spirits rise)
- テンションが下がる (to feel down, spirits fall)
- テンションが高い (to be in high spirits, energetic)
- テンションが低い (to be in low spirits, unmotivated)
- ハイテンション (high energy, hyper)
- ローテンション (low energy, subdued)
- テンション高め (somewhat high energy)
Register: Casual, colloquial. Very common in everyday conversation, especially among younger speakers.