2. Which company is the best and cheapest ?

3. Most companies seem to offer free incoming calls. Is that ALL incoming local as well as international?
4. How is bill settled at the time of reurn ?

thanks

It is cheaper to pick up at Narita as they charge extra for delivery.

Is delivery possible in malaysia?

I'm not sure, I only recall companies that ship to the US, but you can check around

2. Which company is the best and cheapest ?

I haven't used different companies (I always end up getting softbank) but typical prices are around 200 yen/day for the phone and 100 yen/min for outgoing domestic calls. Here's a list of rental outlets at Narita so you can pricecheck:

http://www.narita-airport.jp/en/guide/service/list/svc_19.html

3. Most companies seem to offer free incoming calls. Is that ALL incoming local as well as international?

Yes

4. How is bill settled at the time of reurn ?

1. is it possible to take delivery in osaka and return in narita.

thanks

Yes, some companies have kiosks at both airports, or allow returns through the mail.

renting at the airport you may get a cheaper daily rate, but the call charges will be very very high, e.g. 300 yen per min to the US with Softbank Global Rental.
Overall it will be cheaper to order from somewhere like Rentafone Japan before you go.

Softbank is a bad example as they have one of the highest international calling rates of all the services offered at Narita. Other companies, such as G-call have a significantly more reasonable 70 yen/min to the US.

Your best bet is to figure out your intended usage and then choose a service that fulfills your needs. If you only want the phone for emergencies or will primarily be receiving calls, then go with something with a low daily rate. If you are a heavy user than plans with higher daily rates typically have lower calling costs (Rentafone Japan included).