相 - Ministers of Sumo Make an Appearance Together

Readings:

あい - each other, mutual, together

そう - appearance, aspect

しょう - minister of state, councilor

Compounds:

相変わらず　 あいかわらず　

血相　 けっそう　

首相 しゅしょう

Sentences:

相変わらず、東大生は、難しく考えるねぇ
(from http://revilog.com/2008/01/011108.html)

血相を変える

首相の正式名称は各国で異なるが、それが首相に相当する官職であれば、日本では一律に「首相」と呼ぶ慣習になっている。
(from http://ja.wikipedia.org/wiki/%E9%A6%96%E7%9B%B8)

Translations:

As usual, Tokyo-U students make simple things difficult for themselves

Change his/her expression

The formal title of a "prime minister" is different in each country, but in Japan the media is in the custom of calling all of them "Shushou" if their positions are equivalent to prime ministers.
(Did you see the other compound in this sentence? 相当, そうとう, means suitable, fair, tolerable.)

Bonus:

Sumo contains 相 as well! In 相撲 it takes on an uncommon す sound.

My thanks to http://www.jlptstudy.com/2/index.html and http://www.thejapanesepage.com/kanji/kanji/a.htm for kanji compounds.