I love ramen houses because I love my noodles, especially good noodles, and one of the things I love is good JAPANESE ramen noodles.
Arigataya Ramen house is pretty authentic in its noodle making, encouragingly similar to ones from Japan and the broth is yummy and it's a fast satisfying meal, esepcially when you are really hungry and its lunchtime.
It's located on Roe street in Northbridge, you can locate it by its yellow sign which is written in Japanese (with little romanised Japanese at the bottom).
The noodle house is simple, the staff friendly and the menu - a large variety of noodles to choose from, from ramen to udon. On top of that there is a decent amount of other japanese dishes from katsu, teriyaki, Japanese curry, entrees like takoyaki and gyoza.
Overall, it's one of the few good ramen houses in Perth, but probably one that offers a variety of ramen noodle options. Definately one to try and to dine at if you ever in Northbridge and it won't blow the budget at around $10-$15 for a satisfyingly big bowl.