REDU format ruling
Bad Reaction to Simochi

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)As long as this card remains face-up on the field, any effect of increasing your opponent's Life Points is changed to inflict the same amount of points in damage to your opponent's Life Points.
Rulings
As long as this card remains face-up on the field, any effect of increasing your opponent's Life Points is changed to inflict the same amount of points in damage to your opponent's Life Points.
- The Continuous-like Effect applies while this card is face-up on the field. It does not activate.
- This effect is not cumulative. If you control 2 copies of Bad Reaction to Simochi and your opponent activates Dian Keto the Cure Master, they only take 1000 points of damage [REF].
- VS. Prime Material Dragon: if both Bad Reaction to Simochi and Prime Material Dragon are on the field when Player A's Upstart Goblin resolves, Player B will gain 1000 Life Points (gains / damage happen normally) [REF].
- These rules apply similarly to Nurse Reficule the Fallen One (erratum: Darklord Nurse Reficule).
- If you control this card on the field and activate Rain of Mercy (which makes both players gain 1000 LP): you gain 1000 Life Points and your opponent takes 1000 points of damage.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.