Spashland Obara has an Olympic-sized pool and hot baths.
White Cube in Shiroishi has concerts and events throughout the year (an annual kokeshi exhibition too).
Shichikashuku Ski Area – offers skiing at a great price. In the warmer seasons cottage and campgrounds are available.
Karaoke a very unique and fun Japanese entertainment form found pretty much everywhere.
Big Budda on the hill in Funaoka.
Camping- there are various campsites throughout the Sennan area and Miyagi. Typically one can rent anything they would need from a campsite or invest in camping gear if you plan on doing a lot of camping.
Fukuoka to Ogawara river walk especially during hanami (cherry blossom season). Stalls and picnics are set-up on the banks of the river in Ogawara around hanami.
Heartland Farms in Zao town especially in spring time.
Kokeshi Museum in Zao where you can paint your own kokeshi doll.
Kozoji (Kozo temple). It's the oldest building in Miyagi.
Michinoku no Koen (Michinoku Park) is located in Kawasaki. There is a bus that will get you there from Sendai. It's supposed to be an example of Tohoku recreational living. It's huge, offers paddle boating, frisbee golf, yoga ball pits and a children's playland with go-carts. There are also traditional Japanese historical houses and a small petting zoo with lambs.
Mt. Zao is home to great skiing on both the Miyagi and Yamagata sides of the Zao range. There is also Okama (the crater lake) accessible through the Miyagi side and winter "snow monsters" which are best seen on the Yamagata side of things.
Onsen- (another plug for onsen, see entertainment). Shiroishi has lots of good onsen. There are two main areas near Shiroishi (Obara and Kamasaki). At Obara Izumiya is a good hotel. At Kamasaki, it's Suzukiya. At both you can get an onsen for 500 yen and they have good rotenburo (outdoor baths).
Shichikashuku is known for it’s famous dam, skiing, and beautiful scenery.
Shiroishi Castle and Samurai House are both within walking distance from the train station. Shiroishi Castle and its surrounding grounds are particularly nice during hanami (cherry blossom season) and when the leaves change colors in the Fall (Novemberish). They are also less crowded and more pleasant then some other scenic spots at those times of year.
Takekome Shrine in Iwanuma which holds the biggest new years festival in the area.
Festivals & Special Events
Check with locals in your town for dates festivals and fireworks.
Funaoka – fireworks in July
Inomi-kai on the Abukuma River (This fall event focuses on eating potato soup outdoors. You can book a boat on the Abukuma River and have a 2-hour tour/ soup-eating trip.)
Kakuda summer festival in August.
Kanadzu Tanabata is pretty famous. It is nice if you want a localized version of the Sendai stuff.
Murata has a big festival on the second weekend in October.
Shiroishi has quite a few events on their home page (http://www.city.shiroishi.miyagi.jp)
The fireflies and lantern festivals were quite good.