We visited Itosho on a special occasion and had been really looking forward to trying something new - our regular shojin joint is Bon so inevitably it got compared. Unfortunately the comparison was not in Itosho's favour.
The austere vibe here makes it slightly more zen than what is ideal for a special occasion - simplicity that verges dangerously towards the realm of plain boredom. Which is ok if the food is fabulous, but it's equally as plain. Probably more true to the cuisine's origins, but for a meal at this price point, we were still a bit hungry at the end and were less than overwhelmed by what we had seen.
If you are looking to try Buddhist temple cuisine in Tokyo your best bet is Bon, which is up there with the very best (in fact it's really hard to beat). Other than that, Kyoto is where it's all at.
Cons: too simple for a special meal, over-priced, we left feeling hungry