Ramen Fujimaru is a fairly "informal" store some distance north and west of the west exit of JR Ikebukero Station. It has a large orange awning and is visible from a fair distance away, along a road (under the highway) of mostly warehouses etc. Inside they had a lot of loud music playing. The chashu ramen there was probably one of the biggest bowls of the "shou" size that I have ever had from any ramen shop, Jiro-like or otherwise, in my entire time here, for 950 yen. It was full of linguine size noodles with a very "coarse" texture and a medium amount of taste. Remember that the thinner the noodles, the more of them they can cram into the bowl. The broth was quite thick and more like a shoyu taste than a tonkotsu taste, with a very thick clear layer of oil on top. The pork was probably 50% or more fat and I ended up leaving a lot of it in the bowl. You have to spoon a lot of the broth over the noodles and moyashis in order to get everything to a common temperature and get started. It's a very hot, very greasy and messy bowl and there will be food all over the counter when you are done. While you can get extra abura in a separate dish, if you go here I instead recommend that you get the small dish of shoga in shoyu that is available according to the orange toppings sign in the back. It's intended to be put over the top of the moyashis. Self-service oshiboris are in a large milk crate in the back of the store next to the bathroom. This store's employees will ask you to move if necessary in order to create a continous space for more customer groups to come in, so if they are talking to you and motioning to another seat, take the hint. However I have to say they were very polite and friendly, as though I was the first gaijin that they had seen for a long time. Note the benches outside where you should be waiting before they motion to you to come in.
Livedoor Gourmet page
Diddlefinger Map (English labels)