When it comes to the term Baby Shop, it includes the maternity-related items for expected mothers. Here I listed the baby shop both for new and second hand items.
For specialized new item Baby shops
1) Akachan honpo (アカチャンホンポ)Stores, click here (Japanese)
Sapporo ESTA branch
JR-ESTA Tower, 7th Floor
Sapporo-shi Chuo-ku Kita 5-jou Nishi 2-1
Tel : 011-223-0631 Hour : 10:00~21:00
Atsubetsu Branch
Sapporo-shi Atsubetsu-ku Atsubetsu Chuo5-1-9-1
Tel : 011-896-5501 Hour : 10:00~19:00
Tonden Branch
Ito Yookadoo Tonden Mall, 2nd Floor
Sapporo-shi Kita-ku Tonden 8-jou 3-5-1
Tel : 011-774-1915 Hour : 9:00~22:00
2) Nishi matsuya (西松屋) Baby Kids Stores, click here (Japanese)
Sapporo Shin Kotoni Branch
Sapporo-shi Kita-ku Shinkotoni 1-jou 13-choume 16-25
011-765-5508 AM10:00~PM8:00
Tonden Branch
Sapporo-shi Kita-ku Tonden 8-jou 7-choume 10-27
011-774-5231
Shiroishi Branch
Sapporo-shi Shiroishi-ku Kikusui 8-jou 4-choume 2-15
011-815-6267
Kiyota Branch
Sapporo-shi Kiyota-ku Kitano 6-jou 2-choume 14-ban 2
011-881-3373
Ishiyama Branch
Sapporo-shi Minami-ku Ishiyama 2-jou 9-choume 7-ban 62-gou
011-593-4119
Hoshioki Branch
Sapporo-shi Teine Yamaguchi 478 Banchi 1 E-3
011-681-2170
3) Birthday (バースデイ)
Sapporo-shi Kiyota-ku Hiraoka 3-jou 1-choume 10-1
For specialized second hand Baby shops
1) B.Kid, click here (Japanese)
Sapporo-shi Kita-ku Tonden 6-jou 6-3-14
Tel : 011-775-6993 Hour : 10:00~20:00
2) Bons Recycle Shop
-Nakanoshima Branch
Sapporo-shi Toyohira-ku Nakanoshima 2-jou 4-choume 1-22
Tel : 0120-855-227 Hour : 10:00~19:00
- Yamanote Branch
Sapporo-shi Nishi-ku Yamanote 3 -jou 4-choume 1-29
Hour: 10:00~19:00
And others, click here (Japanese)