Given a document, find the main entity about whom the author is writing. Write the full name if mentioned in the text. Note that URLs in the text have been replaced with [Link].

Q: Rihanna  has emerged as the unlikely inspiration behind Arsenal's thumping 5-1 win against Everton.
 The singer  was at the Emirates to watch the match and enjoy the Gunner's work  work  work  work  work ethic.
After the match   she  posed with midfielder  Mesut Ozil  who described  her  as the team's "lucky charm".
The German said he was "still unbeaten with Riri" - a reference to when  she  came to watch the 2014 World Cup Final between Germany and Argentina.
Ozil himself couldn't get on the scoresheet but with  Rihanna  pulling the inspirational strings during a pre-match meet and greet  other players stepped up.
It's just a shame that whoever was looking after  her  social accounts still referred to the game as "soccer".
After the game  manager Arsene Wenger seemed to play down the importance of  Rihanna 's contribution  focusing instead on his side's "penetration and sharper game".
Given Arsenal's up and down season  there are probably high level talks with  Rihanna 's people to see if  her  schedule allows any more trips to watch the team - with one eye surely on  their  next Europa League match  away at Ostersunds FK.

A: Rihanna
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Q: Chiefs OLB Justin Houston (50) and DL Chris Jones sack Broncos QB Trevor Siemian on Monday night. (Photo: Ed Zurga  AP)
KANSAS CITY  Mo. â  Justin Houston âs once-perfect team had lost consecutive games after a pair of uncharacteristic showings. The Kansas City Chiefs defense couldnât stop anybody  and the offense suddenly lost its effectiveness in the rushing department  which had served as a calling card during the team's 5-0 start.
 Houston   a seventh-year veteran and one of the longest-tenured Chiefs  looked around the locker room  diagnosed the problem and decided he had to speak up.
âIâm from a big family  so I understand there are times to follow  and there are times to lead. There are times to speak up â  Houston  told USA TODAY Sports after Monday night's 29-19 defeat of the Denver Broncos. âWe just werenât having fun.
And  most importantly to  Houston  and his teammates  the Chiefs had fun in the process.

A: Justin Houston
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Q: Ozawa -- regarded by many pundits as the power behind the throne occupied by Prime Minister Yukio Hatoyama -- is now expected to stay on as DPJ secretary general as the party heads into upper house elections in July.
 A bare-knuckle political fighter who defected from the conservative party  Ozawa has denied any wrongdoing  repeatedly saying that he had left the details of any funds transactions up to his secretaries.
 Hatoyama again defended Ozawa  whom he replaced as DPJ president last year after Ozawa stepped down over a separate political funding scandal  in which he also professed his innocence.
 "He has offered explanations in questioning by prosecutors " the premier told reporters. "He has also held many press conferences on this issue. I think he has accounted for himself to the best of his knowledge."
 An unidentified DPJ executive told Jiji Press: "We are now over the hump -- no more pressure for him to step down."
 Opposition lawmakers carried on their attacks against Ozawa.
 Political observers said that even if Ozawa is vindicated  the funds scandal will inevitably affect the party in the upper house elections  in which the DPJ hopes to achieve sole control of parliament.
 "I don't think many people will be convinced that Ozawa was perfectly clean  even if that is the conclusion " said Tomoaki Iwai  politics professor at Nihon University. "Now it's the public's turn to give its verdict."

A:
Ichiro Ozawa
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