Usually you need to prepare 4-6 month of monthly rent for the initial costs of renting a place. Monthly rent is the rent itself + management fee.
初期費用
Initial costs to rent a place
共益費
Management fee. The money to maintain your place.
家賃 (+共益費)
Rent. Usually they take the month you moved in (前家賃、当月分), depends on how many days in the first month (日割家賃), and the next month rent in advance (翌月分の家賃).
敷金
Deposit (0 ~ 3 month)
Usually is about 1 month. This is used to restore the room into original state when you finished the contract. The money left after cleaning will return to you.
礼金
Gift money (0 ~ 3 month)
火災保険料
Fire insurance. ¥10000 - ¥30000.
家賃保証会社加入料
Gurantor company fee.
仲介手数料
Fee for agent. 0-1 month.
クリーニング代
Money to clean the place you will move in.
鍵交換代
Key money. Usually ¥10000-¥25000.
Money to make new keys for the place you will move in.
Besides these, you will also need to prepare 引越し費用. Hiring company to move all your belongs from old place to new place. If this is your first time in Japan, you will need to buy furnitures and appliances (washer, bed, curtain).
I have heard of but they are not common.
決済金
The money needs to pay after contract signed
手付金
A money to reserve the property; Rare
消毒費用
24時間サポートサービス
引越挨拶手土産品
Omiyage for your neighbors.
家財保険