44. Are there limits on traditional media advertising spending in relation to election campaigns?

Source: 
公職選挙法, 1950 (2022改正)
Public Offices Election Act, 1950 (as amended by Act No.68 of 2022)

第百四十九条　衆議院（小選挙区選出）議員の選挙については、候補者は、総務省令で定めるところにより、同一寸法で、いずれか一の新聞に、選挙運動の期間中、五回を限り、選挙に関して広告をし、候補者届出政党は、総務省令で定めるところにより、当該都道府県における当該候補者届出政党の届出候補者の数に応じて総務省令で定める寸法で、いずれか一の新聞に、選挙運動の期間中、総務省令で定める回数を限り、選挙に関して広告をすることができる。
２　衆議院（比例代表選出）議員の選挙については、衆議院名簿届出政党等は、総務省令で定めるところにより、当該選挙区における当該衆議院名簿届出政党等の衆議院名簿登載者の数に応じて総務省令で定める寸法で、いずれか一の新聞に、選挙運動の期間中、総務省令で定める回数を限り、選挙に関して広告をすることができる。
３　参議院（比例代表選出）議員の選挙については、参議院名簿届出政党等は、総務省令で定めるところにより、参議院名簿登載者の数に応じて総務省令で定める寸法で、いずれか一の新聞に、選挙運動の期間中、総務省令で定める回数を限り、選挙に関して広告をすることができる。

第百五十一条の五　何人も、この法律に規定する場合を除く外、放送設備を使用して、選挙運動のために放送をし又は放送をさせることができない。

Article 149. With respect to the election of members of the House of Representatives (elected from single-seat constituencies), candidates shall, in accordance with the provisions of an ordinance of the Ministry of Internal Affairs and Communications, place advertisements concerning the election during the election campaign period, limited to five times, in one newspaper of their choice, using the same dimensions. Candidate-registered political parties may, in accordance with regulations established by the Ministry of Internal Affairs and Communications, place election advertisements in any one newspaper during the election campaign period, limited to the number of times specified by the Ministry of Internal Affairs and Communications, in the size specified by the Ministry of Internal Affairs and Communications according to the number of candidates registered by the candidate-registered political party in the relevant prefecture.
2. For elections of members of the House of Representatives (elected by proportional representation), parties that have submitted a House of Representatives list, etc., may, in accordance with the provisions of the Ordinance of the Ministry of Internal Affairs and Communications, publish election-related advertisements in any one newspaper during the election campaign period, limited to the number of times specified by the Ordinance of the Ministry of Internal Affairs and Communications, in the size specified by the Ordinance of the Ministry of Internal Affairs and Communications according to the number of persons listed on the House of Representatives list of said party that has submitted the list in said electoral district.
3. For elections of members of the House of Councillors (elected by proportional representation), a political party, etc. that has submitted a House of Councillors list may, in accordance with the provisions of an ordinance of the Ministry of Internal Affairs and Communications, publish advertisements concerning the election in one newspaper, in the dimensions specified by an ordinance of the Ministry of Internal Affairs and Communications according to the number of persons listed on the House of Councillors list, during the election campaign period, limited to the number of times specified by an ordinance of the Ministry of Internal Affairs and Communications.

Article 151-5. No person may use broadcasting facilities to broadcast or cause broadcasts to be made for the purpose of election campaigning, except as provided for in this Act.

yes, for political parties and yes, for candidates.

There is a limit on how many times a party and a candidate can place election-related ads on newspapers.  A candidate or party is banned from using broadcasters for election campaigning, except the free broadcasting (as noted in 34 above).