utahta

This plugin inserts social share links at the top or bottom of each post. 
For theme developers, social share links can be added by PHP code or by using shortcode. Check documentation for this use-case.
This plugin documentation can be found <a href="https://github.com/utahta/WP-Social-Bookmarking-Light/wiki" rel="nofollow ugc">here</a>.
This is the list of used social sites:
<ul>
<li>Hatena</li>
<li>Facebook Like Button</li>
<li>Facebook Share Button</li>
<li>Facebook Send Button</li>
<li>Twitter</li>
<li>Tumblr</li>
<li>Google Bookmark</li>
<li>Google +1</li>
<li>Delicious</li>
<li>Digg</li>
<li>reddit</li>
<li>LinkedIn</li>
<li>Instapaper</li>
<li>StumbleUpon</li>
<li>mixi Check</li>
<li>mixi Like</li>
<li>GREE Social Feedback</li>
<li>atode (toread)</li>
<li>LINE</li>
<li>Pocket</li>
<li>Pinterest</li>
</ul>

WP Social Bookmarking Light

This plugin inserts social share links at the top or bottom of each post.

makoto_kw

This plugin displays hatena bookmark comments on entry by using HatenaBookmarkBlogparts. 
HatenaBookmarkBlogparts is here: 
http://d.hatena.ne.jp/keyword/%A4%CF%A4%C6%A4%CA%A5%D6%A5%C3%A5%AF%A5%DE%A1%BC%A5%AF%A5%B3%A5%E1%A5%F3%A5%C8%C9%BD%BC%A8%A5%D6%A5%ED%A5%B0%A5%D1%A1%BC%A5%C4

Hatena Bookmark Comment

Displays hatena bookmark comments on entry by using HatenaBookmark Blogparts.

WP Social Bookmarking Light vs Hatena Bookmark Comment