Nakano has a JR station (JR Nakano) that can be accessed via the Chuo and Chuo-Sobu Line.
It can also be accessed using the Tokyo Metro Tozai Line.
Nakano Broadway is a 3 storey building that houses the origin of otaku culture. A large Mandarake can be found in this building that contains some very rare doujins and merchandise. There are also multiple TRIOs and Robot+Robot stores scattered inside, as well as Games Workshop, cosplay, and multiple antique and vintage stores. You can also find other otaku stores here such as die cast model cars etc. In the far corner of one of the levels is a Character Pantsu store where you can get gacha pantsu and buy character specific pantsu as well.
TRIO is a store that specializes in idol otaku specific goods and merchandise, but they also house a selection of extremely rare anime posters that are usually not for sale that are used to advertise in retail stores.
The Mandarake stores here are special, as each Mandarake on each level specializes in different things such as doujinshi, figures, and even used game cartridges. You can find the $5000 gold megaman cartridge here.