rent a car with tocoo and force to pay TAS

I read
http://www2.tocoo.jp/en/contents/info/tas

still I don't get it anyway.

Can anybody please explain in short and more clearer
what is the diffirent between tas and Compensation Coverage that I paid in additional too.

TAS is their umbrella term for all the additional, optional services that Tocoo offers. These include add-ons such as supplementary insurance, wifi rental, or translator support that you can purchase in addition to your rental car.

thank you for answering me.

I think it's rather hard to book with tocoo, tried it every month, and the reply is always non available, so I went direct with the car rental company, I have a reservation with Nissan, and the price works out very similar, and the coverage is much clearer.

Nissan and Toyota are the main ones, which are available all around Japan.