@ElJefe: It's Siddham. Many of the Sanskrit Buddhist texts that made their way into East Asia were written in the Siddham script, and it is still used to this day in esoteric schools of Buddhism in Japan, so there's a strong association between Sanskrit and the Siddham script in Japan.
@SystemicChaos oh, makes sense. I can read modern sanskrit which is written in contemporary devanagari in bombay style (shaili) but old stuff (I think Siddham lipi was used for middle sanskrit) i cannot read.
Cheers! And good work!