[4] She was removed from office by way of an 8–6 decision by the Supreme Court over a quo warranto petition, rendering her appointment as chief justice null and void.

[9] Sereno was born on July 2, 1960, in Manila, to Margarito Aranal of Siasi, Sulu, and Soledad Punzalan of Bay, Laguna who served as a public school teacher.

[11] A scholarship allowed her to apply at the Ateneo de Manila University where she had the options of taking either Political Science or Economics.

[3] At the time of her appointment to the Supreme Court in 2010, Sereno was executive director of the Asian Institute of Management Policy Center.

She was also the president of Accesslaw Inc., had taught at University of the Philippines College of Law for 19 years, and served as a consultant for the United Nations, World Bank, and US Agency for International Development.

[17] On August 24, 2012, President Aquino announced his appointment of Sereno as the new chief justice of the Supreme Court, replacing Renato Corona, who was removed from office in May 2012 after being convicted in an impeachment trial.

Sereno voted against several of President Rodrigo Duterte's proposals, such as declaring martial law and burying Ferdinand Marcos in a cemetery reserved for national heroes.

In addition Solicitor General Jose Calida filed a quo warranto petition to invalidate her appointment as chief justice over alleged lack of integrity.

Both the impeachment proceedings and quo warranto petition cites Sereno's alleged failure to properly declare her Statement of Assets, Liabilities and Net worth (SALN) and was also responsible for tax misdeclarations and unauthorized expenses.

She emphasized the importance of basing legislative decisions on facts, particularly when addressing issues affecting vulnerable sectors of society.

In a statement, she said: "Wala po akong reklamo kung may mga iba't ibang stakeholder organizations na puposisyon para o kontra sa isang panukalang batas namin dito.

Ibig sabihin, sinasabi nila, magandang pag-isipan ang plano nyo, mag-restrain kayo and in fact, abstinence is a good standard for Singaporean youth.

"[30] Sereno has expressed concerns about international programs promoted by organizations such as UNESCO, UNFPA, and UNICEF, which she believes could hypersexualize children at an early age.