Overnight bus from Narita to Osaka

Dear friends,

My flight is planned to arrive at Narita airport at 18:40... am I going to be able to clear customs and take the overnight bus to Osaka?

Please help.. this is going to be my first time n Japan.
Thanks in advance.

Which date?
Which bus? (Which bus stop?)

Why night bus?
You may reach Osaka on the day night by domestic flight from NRT to KIX if not full.

Basically, if you can change the ticket from Morocco(?) to KIX, you should do that.

I couldn't find a comprehensive answer, but at least Nankai bus is operating night bus direct from Narita Airport to Osaka.

http://www.nankaibus.jp/express/09.html#key02

Narita Airport Terminal 2 21:35
Narita Airport Terminal 1 21:40
JR Osaka station 07:29
Osaka Namba bus terminal 07:49

I couldn't find English timetable.

Check the schedule for your specific day on Willer Express website, but I think the only night bus leaving directly from Narita leaves at 21:40. So with 3 hours after you plane lands at 18:40, you should have plenty of time.

The bus is about 8000y. Often you can book a flight to KIX airport near Osaka for about that same price premium. Of course you'd have to pay for a hotel that night, but then at least you might have a chance at sleeping off the jet lag. And I don't know where you are flying from, but my recent flight to Japan took 13 hours and the last thing I wanted to do after landing is get on a bus for 10 hours more!

From what place will you arrive to Japan?
Have you confirmed that you cannot choose Kansai Airport [KIX]?
(It is less than 1 hour to get from KIX to Osaka City by railway.)

To travel from Narita Airport [NRT] for Osaka City all by bus,
usually you change buses somewhere in Tokyo (#).

(As is mentioned by frog1954,
there is a bus departing from Narita Airport,
on the line which is operated jointly by Chiba Kotsu and Nankai Bus;
however it seems you cannot book there a bus ride through a website in English.)

Personally I cannot recommend a night bus ride just after a long flight to Japan,
especially not for first-time Japan travelers.

The level of quality of expressway bus services
depends on routes, operator companies and price ranges.
(Jumping at a low price may result in putting up with some inconveniences.)
The overnight bus route connecting Tokyo and Osaka City is highly competitive.

(#)
e.g.
(1) Bus ride from Narita Airport (Terminal 1 , 2 or 3)
to Tokyo Station (Yaesu South Entrance)
http://accessnarita.jp/en/home/#timetable-title-3386
(2) Walking for about 160 meters between the bus stops
https://www.google.co.jp/maps/dir/35.6799036,139.7697009/35.6799073,13...
(3) Bus ride from Tokyo Station (Yaesu Entrance)
https://japanbusonline.com/en/CourseSearch/11700010073

however it seems you cannot book there a bus ride through a website in English

You can book it on Willer's website (it can be used to book not only Willer buses but also those of some other companies).

http://willerexpress.com/en/

Thank you so much for your comments. You were really of a great help.
I have made up my mind now thanks to your clarification.