There are private real estate agents around Waseda University, who can offer you a variety of accommodation options. You can also find lease information magazines in bookstores. Please note that when you use real estate agents and sign a lodging contract, you will need to pay Key Money called “reikin” (non-returnable) and Deposit Systems called “Shikikin” (bond), which is a unique custom in Japan(*). Therefore, please talk to your guarantor or people who are familiar with this custom in advance before you make your decision.
* For details, please refer to the following link:
The chapter of “Housing” in “The International Student Handbook” written in both Japanese and English.