Katsushika to Live in Tokyo

Hello- I am soon moving to Tokyo for a term of two years. While I am not going to rent my place before seeing it, I have been checking places online so that I have a better idea where to start looking once I arrive in Tokyo. I am coming from a giant city - Istanbul with very long commutes everyday to get anywhere within the city. So I am not afraid living away from the center and reduce the rent fee per square meter. While looking at cheaper but bigger options, many places in Katsushika ward came up. I wanted to see if anyone is familiar with the ward and can advice on safety (for solo women). I don`t need to be close to any entertainment but some grocery shops, restaurants would be nice to have around. I wont have school or work every day so potentially long commute to the city does not worry me much as long as the neighborhood is nice and the apartment is adequate. I have been to Japan and Tokyo many times before and I am aware of the countries much better crime rate compared to other big cities in the World including mine.

Istanbul 15 million. Tokyo 37 million.
Katsushika or Adachi or Edogawa were never particularly attractive spots for me when I was hunting for somewhere to live, but that was me, and different areas all have their own particular vibe. Over the last decade I've stayed in a lot of places and visited quite a few neighbourhoods (certainly not all of them), and I had a few ideas before settling into my current spot.
For heading out of the central city, yes, you can avoid the very high rents, but it quickly becomes pretty flat in terms of savings vs commute time. A huge part of the of the city can be accessed in under an hour and while there are 90 minute commutes (and longer), probably the main item to try to avoid is too many transfers -one or two isn't too bad. Probably a consideration is if you have to traverse the middle of Tokyo each day or not - do you know where you will be working?
Cost of accommodation is also linked to how far you have to walk to the nearest train station. And if you have been in Tokyo/Japan many times, you should know there are shops/restaurants around stations - even in the outer areas - that's how the place is arranged.

Thank you this is very helpful. I think I will have to cover/ visit on foot all potential neigborhoods before settling on an apartment. In terms of Istanbul v. Tokyo - I was not talking about the population, which is a matter of density rather than a size but the geographical size of the city. Istanbul is 5461 km2 v. Tokyo being 2188 km2 and in Istanbul we need to cross continents in certain cases to go to work (from Asia to Europe). So I think I can probably handle Tokyo quite easily when it comes to size.

That was actually my point, Tokyo, despite being large is easy to get around - it just takes time.
The numbers I would have quoted for size are 5,343km2 and 13,572km2 for Tokyo, but definitions vary.