I thought it would be interesting to have make a list of manga and anime where these names appear. Strangely enough there seem to be quite a lot (thank you Google and wikipedia)
Here are the Saotomes and Tendos I've found
Haruna Saotome (Negima)
Zenjuro Saotome (Beelzebub)
Junko Saotome (Nana)
Hinata Saotome (Usotsuki Lily)
Taifu Saotome (Saotome Typhoon)
Alto Saotome (Macross Frontier)
Hatsuki Saotome (Lives)
Roman Saotome (Sket Dance)
Michiru Saotome (Getter Robo)
Jin Saotome (Cyberbots) (game)
Shining Saotome (Uta no Prince-sama)
Kazuko Saotome (Puella Magi Madoka Magica)
Ichigo Saotome (Mayo Chiki!)
Kazuya Saotome (Hand Maid May)
Rei Saotome (Yu-Gi-Oh)
Hijiri Saotome (Virgin Star)
Makoto Saotome (Kannazuki no Miko)
Rushuna Tendo (Grenadier)
Soji Tendo & Juka Tendo (Kamen Rider Kabuto)
Mayumi Tendo (Battle Royale)
Gai Tendo (Buriki One) (game)
Ran Tendo (Narue no Sekai)
Here are the Saotomes and Tendos I've found
Haruna Saotome (Negima)
Zenjuro Saotome (Beelzebub)
Junko Saotome (Nana)
Hinata Saotome (Usotsuki Lily)
Taifu Saotome (Saotome Typhoon)
Alto Saotome (Macross Frontier)
Hatsuki Saotome (Lives)
Roman Saotome (Sket Dance)
Michiru Saotome (Getter Robo)
Jin Saotome (Cyberbots) (game)
Shining Saotome (Uta no Prince-sama)
Kazuko Saotome (Puella Magi Madoka Magica)
Ichigo Saotome (Mayo Chiki!)
Kazuya Saotome (Hand Maid May)
Rei Saotome (Yu-Gi-Oh)
Hijiri Saotome (Virgin Star)
Makoto Saotome (Kannazuki no Miko)
Rushuna Tendo (Grenadier)
Soji Tendo & Juka Tendo (Kamen Rider Kabuto)
Mayumi Tendo (Battle Royale)
Gai Tendo (Buriki One) (game)
Ran Tendo (Narue no Sekai)