Staying in Japan for 6 months without a visa

I want to stay in Japan for 6 months and I know that British citizens can stay for 90 days without a visa and then apply for an extension to stay for 6 months. However, I am worried about initially applying for entry to the country with a return ticket 6 months after my arrival. Will I have trouble getting into Japan?

If you answer that you are planning to stay six months, they might ask you if you have enough funds to travel as long as six months, and possibly ask to see the ticket. There is no guarantee. Have you done extensive travel like this before?

I will be able to show them my bank details and a return ticket within 6 months of my arrival. Might that be enough?
No, this is my first time travelling for such a long period.

You are very very likely to get 90 days landing permission into your passport alright upon entry.

Once someone I know from another country whose nationals can stay up to 6 months (with an extension) on Temporary Visitor status in Japan, was given 3 months upon entry alright, but because he originally wanted to stay for 6 months, he (he speaks Japanese) asked if he could get an extension by... let's say, giving a reason such as studying the language further. The immigration officer did not give a very encouraging answer. I remember he did not have to show his ticket, though. The officer openly said that they did not actively reciprocate the stay granted to Japanese (Japanese traveling to his home country would get 6 months).

Considering that, it might prove to be useful later if you have a return ticket that can be changed (I mean the travel out of Japan). And if you do come with a return ticket with a fixed date on it, please be sure that it is within 180 days :)

You will be given 90 days when entering, as everybody else does except those who only get 15 days.

You will be given 90 days when entering, as everybody else does except those who only get 15 days or those who are flat out denied entry.

There fixed it.